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  • 101.
    Liao, Yu-feng
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Li, Wen-jiang
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Synthesis of CdSe quantum dots via paraffin liquid and oleic acid2008Ingår i: J ZHEJIANG UNIV-SCI A, ISSN 1673-565X, Vol. 9, nr 1, s. 133-136Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper reported an efficient and rapid method to produce highly monodispersed CdSe quantum dots (QDs), in which the traditional trioctylphosphine oxide (TOPO) was replaced by paraffin liquid as solvent and oleic acid as the reacting media. The experimental conditions and the properties of QDs had been studied in detail. The resulting samples were confirmed of uniform size distribution with transmission electronic microscopy (TEM), while UV-vis absorption and photoluminescence (PL) spectra clearly indicated that such synthesized QDs had good fluorescence properties.

  • 102. Liao, Yufeng
    et al.
    Li, Wenjiang
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Gao, Ying
    A facile way to fabricate CdSe quantum dots coated with silica and the fluorescence property2006Ingår i: Proceedings of International Symposium on Biophotonics, Nanophotonics and Metamaterials, 2006, s. 342-345Konferensbidrag (Refereegranskat)
    Abstract [en]

    Good quality quantum dots (QDs) CdSe were prepared with a novel and non-TOP method. Quantum dots with different sizes ranging from 2 to 5 rim could be obtained by removing aliquots of reaction solution at different time intervals. The quantum dots CdSe (core) -silica (shell) was fabricated by a rnicroemulsion method. Transmission electron microscopy (TEM) images confirmed the well monodispersed QDs and the silica shell around CdSe core respectively. UV-Vis absorption and photoluminescence spectra clearly indicated that both the original QDs and the silica-coated QDs had good fluorescence properties. The quantum dots coated with silica shell are water-soluble and less toxic (due to the silica shell), which are anticipated as fluorescent probes for biosensing and imaging applications such as tumor detection of pre-cancers.

  • 103.
    Lin, Xian Qi
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektroteknisk teori och konstruktion. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Jiang, Yuan
    Jin, Jun Ye
    Yu, Jia Wei
    He, Sailing
    KTH, Skolan för elektro- och systemteknik (EES), Elektroteknisk teori och konstruktion. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Understand and realize an "invisible gateway" in a classical way2013Ingår i: Progress In Electromagnetics Research, ISSN 1070-4698, E-ISSN 1559-8985, Vol. 141, s. 739-749Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We create an invisible gateway simply by putting electric and magnetic superscatterers in a metallic waveguide. The characteristics of the electric and magnetic resonators are analyzed in a metallic hollow waveguide, and the dual-mode superscattering property is discussed in detail to broaden the bandwidth of the invisible gateway. Good agreement is achieved between the simulation and measurement for such an invisible gateway. The present work help readers understand easily how an invisible gateway works (or makes sense) in a classical way without using any complex metamaterial or complicated method of transformation optics.

  • 104.
    Lin, Zhili
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Thylén, Lars
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    An analytical derivation of the optimum source patterns for the pseudospectral time-domain method2009Ingår i: Journal of Computational Physics, ISSN 0021-9991, E-ISSN 1090-2716, Vol. 228, nr 19, s. 7375-7387Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the computational electromagnetics and acoustics, spatially smoothed sources are often utilized to alleviate the aliasing errors in the pseudospectral time-domain (PSTD) algorithms. In our work, an analytical derivation of the optimum source patterns is presented according to the accurately derived expressions of the dominant source-introduced aliasing errors according to the circular discrete convolution and Tailor series expansion method. We quantitatively demonstrate, for the first time in literature, that the aliasing errors can be optimally suppressed and rapidly reduced to the negligible levels by these optimum patterns and with the increment of source cells. We also provide the different implementation schemes of the optimal patterns both for the soft and hard source cases. The numerical calculation and 1D PSTD transient simulations are conducted to verify the excellent performance of these optimum sources.

  • 105. Liu, Kexin
    et al.
    Jiang, Wei
    Sun, Fei
    KTH, Skolan för elektro- och systemteknik (EES), Elektroteknisk teori och konstruktion. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    He, Sailing
    KTH, Skolan för elektro- och systemteknik (EES), Elektroteknisk teori och konstruktion. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Experimental Realization of Strong DC Magnetic Enhancement with Transformation Optics2014Ingår i: Progress In Electromagnetics Research, ISSN 1070-4698, E-ISSN 1559-8985, Vol. 146, s. 187-194Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A passive DC magnetic concentrator is designed with transformation optics (TO) and realized by meta-materials. The passive DC magnetic concentrator based on space compression transformation can greatly enhance the magnetic field in a free space region and can be used for e.g., improving the sensitivity of magnetic sensors and increasing the efficiency of wireless energy transmission. The magnetic property of the medium obtained by TO is extremely anisotropic. To solve this, we use magnetic metamaterials made of alternated high-permeability ferromagnetic (HPF) materials and high-temperature superconductor (HTS) materials. We optimize our structure by conducting simulations using the finite element method (FEM) and experimentally demonstrate a strong, 4.74-time enhancement of the DC magnetic field by our meta-material magnetic concentrator. We also demonstrate that a simplified structure with only HPF materials working at room temperature can still gives 3.84-time enhancement of the DC magnetic field. The experimental results are in good agreement with the numerical simulations based on FEM.

  • 106.
    Lou, Fei
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO.
    Dai, Daoxin
    Thylén, Lars
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Wosinski, Lech
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Design and analysis of ultra-compact EO polymer modulators based on hybrid plasmonic microring resonators2013Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 21, nr 17, s. 20041-20051Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ultra-compact EO polymer modulators based on hybrid plasmonic microring resonators are proposed, simulated and analyzed. Comparing with Si slot microring modulator, hybrid plasmonic microring modulator shows about 6-times enhancement of the figure of merit when the bending radius is around 510 nm, due to its much larger intrinsic quality factor in sub-micron radius range. Influences of the EO polymer height and Si height on the device's performance are analyzed and optimal design is given. When operating with a bias of 3.6V, the proposed device has optical modulation amplitude of 0.8 and insertion loss of about 1 dB. The estimated power consumption is about 5 fJ/bit at 100 GHz.

  • 107.
    Lou, Fei
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO.
    Thylén, Lars
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Wosinski, Lech
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Hybrid plasmonic microdisk resonators for optical interconnect applications2013Ingår i: Integrated Optics: Physics and Simulations, SPIE - International Society for Optical Engineering, 2013, s. 87810X-Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we present our theoretical and experimental work on hybrid plasmonic microdisks. The 170 nm wide access waveguide is first simulated and characterized, and shows a propagation loss about 0.08 dB/mu m. 3-D FDTD simulations are then used to investigate the lower limit of the bending radius of the hybrid plasmonic microdisk. Microdisks with radius around 500 nm are fabricated, characterized, and analyzed. The 5th and 4th order resonances are experimentally observed around 1412 nm and 1625 nm. The extinction ratios of the two resonances are measured to be 5.5dB and above 10dB, respectively. The measured intrinsic quality factors are 350 and 110, respectively. Comparisons are also made between the theoretical and experimental results. The demonstrated ultra-small hybrid plasmonic microdisk may find applications in low-power-consumption modulators, nano laser cavities with large Purcell-factor, molecule sensors, and others.

  • 108.
    Lou, Fei
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101).
    Wang, Zhechao
    Ghent University-IMEC, Belgium.
    Dai, Daoxin
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Thylén, Lars
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Wosinski, Lech
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Photonic devices based on silicon hybrid plasmonic waveguides2012Ingår i: 2012 Asia Communications And Photonics Conference (ACP), 2012, s. AS2H.2-Konferensbidrag (Refereegranskat)
    Abstract [en]

    A 170 nm wide hybrid plasmonic waveguide with a loss of 0,08 dB/mu m is demonstrated experimentally. Directional couplers with different gaps and microdisks with 0.5 mu m radius based on such waveguides are also presented.

  • 109.
    Lou, Fei
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO.
    Wang, Zhechao
    Ghent University, Belgium .
    Dai, Daoxin
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP. Zhejiang University.
    Thylén, Lars
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Wosinski, Lech
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Sub-wavelength microdisk resonator based on hybrid plasmonic waveguides2012Ingår i: Information Optoelectronics, Nanofabrication and Testing, IONT 2012, 2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    Based on hybrid plasmonic waveguides, microdisk resonators with radii of 0.5 μm and FSRs of about 200 nm are simulated and experimentally demonstrated. Thermal tuning of the devices in 6 nm range is also presented.

  • 110.
    Lou, Fei
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO.
    Yan, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO.
    Thylén, Lars
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Wosinski, Lech
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Whispering gallery mode nanodisk resonator based on layered metal-dielectric waveguide2014Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 22, nr 7, s. 8490-8502Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper proposes a layered metal-dielectric waveguide consisting of a stack of alternating metal and dielectric films which enables an ultracompact mode confinement. The properties of whispering gallery modes supported by disk resonators based on such waveguides are investigated for achieving a large Purcell factor. We show that by stacking three layers of 10 nm thick silver with two layers of 50 nm dielectric layers (of refractive index n) in sequence, the disk radius can be as small as 61 nm similar to lambda(0) / (7n) and the mode volume is only 0.0175 (lambda(0) / (2n))(3). When operating at 40 K, the cavity's Q-factor can be similar to 670; Purcell factor can be as large as 2.3x10(4), which is more than five times larger than that achievable in a metal-dielectric-metal disk cavity in the same condition. When more dielectric layers with smaller thicknesses are used, even more compact confinement can be achieved. For example, the radius of a cavity consisting of seven dielectric-layer waveguide can be shrunk down to lambda(0) / (13.5n), corresponding to a mode volume of 0.005 lambda(0) / (2n))(3), and Purcell factor can be enhanced to 7.3x10(4) at 40 K. The influence of parameters like thicknesses of dielectric and metal films, cavity size, and number of dielectric layers is also comprehensively studied. The proposed waveguide and nanodisk cavity provide an alternative for ultracompact light confinement, and can find applications where a strong light-matter interaction is necessary.

  • 111. Lou, X. T.
    et al.
    Zhang, Z. G.
    Somesfalean, Gabriel
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Chen, B.
    Zhang, Y. G.
    Wang, H. S.
    Wu, S. H.
    Qin, Y. K.
    Simultaneous detection of multiple-gas species by correlation spectroscopy using a multimode diode laser2010Ingår i: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 35, nr 11, s. 1749-1751Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Simultaneous detection of multiple-gas species has for the first time (to our knowledge) been demonstrated by using a multimode diode-laser-based correlation spectroscopy (MDL-COSPEC) scheme. Concentration measurements of a mixture of CO2 and CO gas were performed by probing overlapping line spectra around 1.57 using an MDL. Species identification and corresponding quantitive analysis were implemented by correlating the recorded absorption signals of the sample gas mixtures with those of the reference gases of particular interest, attaining accuracies of 2% and 1%, respectively. MDL-COSPEC is a generic technique with potential application for simultaneous detection of multiple gases having resolvable narrow lines.

  • 112. Lou, Xiutao
    et al.
    Somesfalean, Gabriel
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Svanberg, Sune
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Zhang, Zhiguo
    Wu, Shaohua
    Detection of elemental mercury by multimode diode laser correlation spectroscopy2012Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 20, nr 5, s. 4927-4938Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We demonstrate a method for elemental mercury detection based on correlation spectroscopy employing UV laser radiation generated by sum-frequency mixing of two visible multimode diode lasers. Resonance matching of the multimode UV laser is achieved in a wide wavelength range and with good tolerance for various operating conditions. Large mode-hops provide an off-resonance baseline, eliminating interferences from other gas species with broadband absorption. A sensitivity of 1 mu g/m(3) is obtained for a 1-m path length and 30-s integration time. The performance of the system shows promise for mercury monitoring in industrial applications.

  • 113. Lou, Xiutao
    et al.
    Somesfalean, Gabriel
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Zhang, Zhiguo
    Wu, Shaohua
    Temperature-Corrected Oxygen Detection Based on Multi-Mode Diode Laser Correlation Spectroscopy2013Ingår i: Journal of Spectroscopy, ISSN 2314-4920, s. 524071-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Temperature-corrected oxygen measurements were performed by using multi-mode diode laser correlation spectroscopy at temperatures ranging between 300 and 473 K. The experiments simulate in situ monitoring of oxygen in coal-combustion exhaust gases at the tail of the flue. A linear relationship with a correlation coefficient of -0.999 was found between the evaluated concentration and the gas temperature. Temperature effects were either auto-corrected by keeping the reference gas at the same conditions as the sample gas, or rectified by using a predetermined effective temperature-correction coefficient calibrated for a range of absorption wavelengths. Relative standard deviations of the temperature-correction coefficient calibrated for a range of absorption wavelengths. Relative standard deviations of the temperature-corrected oxygen concentrations obtained by different schemes and at various temperatures were estimated, yielding a measurement precision of 0.6%.

  • 114. Ma, Yungui
    et al.
    Lan, Lu
    Jiang, Wei
    Sun, Fei
    KTH, Skolan för elektro- och systemteknik (EES), Elektroteknisk teori och konstruktion. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    He, Sailing
    KTH, Skolan för elektro- och systemteknik (EES), Elektroteknisk teori och konstruktion. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    A transient thermal cloak experimentally realized through a rescaled diffusion equation with anisotropic thermal diffusivity2013Ingår i: NPG Asia Materials, ISSN 1884-4049, Vol. 5, nr 11, s. e73-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Transformation optics has made a major contribution to the advancement of modern electromagnetism and related research assisted by the development of metamaterials. In this work, we applied this concept to the thermodynamics using the coordinate transformation to the time-dependent heat diffusion equation to manipulate the heat flux by predefined diffusion paths. Experimentally, we demonstrated a transient thermal cloaking device engineered with effective thermal materials and successfully hid a centimeter-sized vacuum cavity. A rescaled heat equation accounting for all the pertinent parameters of various ingredient materials was proposed to greatly facilitate the fabrication. Our results unambiguously demonstrate the practical possibility of implementing complex transformed thermal media with high accuracy and acquiring several unprecedented thermodynamic functions, which we believe will help to broaden the current research and pave a new path to manipulate heat for novel device applications.

  • 115.
    Mei, L.
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Guan, Z. G.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Zhou, H. J.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Lv, J.
    Zhu, Z. R.
    Cheng, J. A.
    Chen, F. J.
    Lofstedt, C.
    Svanberg, Sune
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Somesfalean, Gabriel
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Agricultural pest monitoring using fluorescence lidar techniques Feasibility study2012Ingår i: Applied physics. B, Lasers and optics (Print), ISSN 0946-2171, E-ISSN 1432-0649, Vol. 106, nr 3, s. 733-740Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The fluorescence of different types of planthopper (Hemiptera) and moth (Lepidoptera), which constitute important Chinese agricultural pests, was investigated both in situ in a laboratory setting and remotely using a fluorescence light detection and ranging (lidar) system operating at a range of about 50 m. The natural autofluorescence of different species, as well as the fluorescence from insects that had been dusted with fluorescent dye powder for identification were studied. Autofluorescence spectra of both moths and planthoppers show a maximum intensity peak around 450 nm. Bleaching upon long-time laser illumination was modest and did not affect the shape of the spectrum. A single dyed rice planthopper, a few mm in size, could be detected at 50 m distance by using the fluorescence lidar system. By employing various marking dyes, different types of agricultural pest could be determined. We suggest that lidar may be used in studies of migration and movement of pest insects, including studies of their behavior in the vicinity of pheromone traps and in pheromone-treated fields.

  • 116.
    Mei, Liang
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Guan, Zuguang
    Somesfalean, Gabriel
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Svanberg, Sune
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Laser-induced fluorescence monitoring of Chinese Longjing tea2012Ingår i: Remote Sensing For Agriculture, Ecosystems, And Hydrology XIV, SPIE - International Society for Optical Engineering, 2012, s. 85311T-Konferensbidrag (Refereegranskat)
    Abstract [en]

    Laser-induced fluorescence (LIF) spectra of a bush and numerous branches of Chinese Longjing tea were investigated remotely with lidar techniques. The intensity ratio between the far red fluorescence (FRF) and red fluorescence (RF) due to the chlorophyll content of the tea branches were analyzed to study the growth conditions in different villages around Hangzhou, China. Dried Longjing tea leaves were also measured by LIF techniques in the laboratory. A chemometric method based on singular value decomposition (SVD) and linear discriminant analysis (LDA) was used to evaluate the tea qualities of the dried tea leaves.

  • 117.
    Mei, Liang
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Larsson, J.
    Svanberg, Sune
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Somesfalean, Gabriel
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Optical porosimetry in wood using oxygen absorption spectroscopy and frequency domain photon migration2012Ingår i: Asia Communications and Photonics Conference, ACP, 2012, s. AS1E.5-Konferensbidrag (Refereegranskat)
    Abstract [en]

    A method to assess the relative optical porosity in wood by a combination of gas in scattering media absorption spectroscopy (GASMAS) and frequency domain photon migration (FDPM) is presented. Samples of balsa and pine wood are studied.

  • 118.
    Mei, Liang
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Lundin, Patrik
    Brydegaard, Mikkel
    Gong, Shuying
    Tang, Desong
    Somesfalean, Gabriel
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    He, Sailing
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Svanberg, Sune
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Tea classification and quality assessment using laser-induced fluorescence and chemometric evaluation2012Ingår i: Applied Optics, ISSN 1559-128X, Vol. 51, nr 7, s. 803-811Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Laser-induced fluorescence was used to evaluate the classification and quality of Chinese oolong teas and jasmine teas. The fluorescence of four different types of Chinese oolong teas-Guangdong oolong, North Fujian oolong, South Fujian oolong, and Taiwan oolong was recorded and singular value decomposition was used to describe the autofluoresence of the tea samples. Linear discriminant analysis was used to train a predictive chemometric model and a leave-one-out methodology was used to classify the types and evaluate the quality of the tea samples. The predicted classification of the oolong teas and the grade of the jasmine teas were estimated using this method. The agreement between the grades evaluated by the tea experts and by the chemometric model shows the potential of this technique to be used for practical assessment of tea grades.

  • 119. Mei, Liang
    et al.
    Svanberg, Sune
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Somesfalean, Gabriel
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Combined optical porosimetry and gas absorption spectroscopy in gas-filled porous media using diode-laser-based frequency domain photon migration2012Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 20, nr 15, s. 16942-16954Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A combination method of frequency domain photon migration (FDPM) and gas in scattering media absorption spectroscopy (GASMAS) is used for assessment of the mean optical path length (MOPL) and the gas absorption in gas-filled porous media, respectively. Polystyrene (PS) foams, with extremely high physical porosity, are utilized as sample materials for proof-of-principle demonstration. The optical porosity, defined as the ratio between the path length through the pores and the path length through the medium, is evaluated in PS foam and found consistent with the measured physical porosity. The method was also utilized for the study of balsa and spruce wood samples.

  • 120.
    Mei, Liang
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Svanberg, Sune
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Somesfalean, Gabriel
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Frequency-modulated light scattering in colloidal suspensions2013Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 102, nr 6, s. 061104-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Frequency-modulated light field fluctuations due to moving particles in colloidal suspensions are examined using heterodyne interferometry. The power spectrum is the combined result of a time-of-flight-related frequency distribution due to light scattering and frequency shifts due to the Doppler effect. An approximation model is developed based on diffusion theory and verified experimentally. The potential for application towards comprehensive diagnosis of both particle dynamics and optical properties of the examined media is discussed.

  • 121. Mo, Lei
    et al.
    Yang, Liu
    Lee, El Hang
    He, Sailing
    KTH, Skolan för elektro- och systemteknik (EES), Elektroteknisk teori och konstruktion. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP. Zhejiang University, China .
    High-Efficiency Plasmonic Metamaterial Selective Emitter Based on an Optimized Spherical Core-Shell Nanostructure for Planar Solar Thermophotovoltaics2015Ingår i: PLASMONICS, ISSN 1557-1955, Vol. 10, nr 3, s. 529-538Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We propose a high-efficiency plasmonic metamaterial selective emitter based on a tungsten (W) spherical core-shell nanostructure for potential applications in planar solar thermophotovoltaics. This structure consists of silicon dioxide (SiO2)-coated W nanospheres periodically distributed on a W substrate and a thin W layer deposited on top. Using a new definition of spectral efficiency, numerical optimization is performed and its optical behaviors are systematically investigated. The numerical results show that our selective emitter has a high emissivity in the short wavelength range below the wavelength corresponding to the bandgap of the back photovoltaic cell and a low emissivity in the long wavelength range beyond it. Its spectral efficiency of 0.39 is much higher than those of other cases without the top W cover layer or the W nanospheres. Such excellent emission selectivity is attributed to the strong photonic interaction within the gaps between the adjacent core-shell nanospheres, the tightly confined optical fields in both the Omega-shaped W-SiO2-W nanocavities, and the bottom nanocavities formed by the W nanospheres and the W substrate. It is also very tolerant toward the thicknesses of the SiO2 layer and the top W cover layer.

  • 122. Mo, Lei
    et al.
    Yang, Liu
    Nadzeyka, Achim
    Bauerdick, Sven
    He, Sailing
    KTH, Skolan för elektro- och systemteknik (EES), Elektroteknisk teori och konstruktion. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Enhanced broadband absorption in gold by plasmonic tapered coaxial holes2014Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 22, nr 26, s. 32233-32244Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Gold absorbers based on plasmonic tapered coaxial holes (PTCHs) are demonstrated theoretically and experimentally. An average absorption of over 0.93 is obtained theoretically in a broad wavelength range from 300 nm to 900 nm without polarization sensitivity due to the structural symmetry. Strong scattering of the incident light by the tapered coaxial holes is the main reason for the high absorption in the short wavelength range below about 550 nm, while gap surface plasmon polaritons propagating along the taper dominate the resonance-induced high absorption in the long wavelength range. Combining two PTCHs with different structural parameters can further enhance the absorption and thus increase the spectral bandwidth, which is verified by a sample fabricated by focused ion beam milling. This design is promising to be extended to other metals to realize effective and efficient light harvesting and absorption.

  • 123.
    Ou, Haiyan
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Zhu, K.
    Hu, Y.
    Fu, H.
    An all-optical frequency up-conversion solution implementing microwave photonic filter in a radio-over-fiber system2008Ingår i: Proceedings of SPIE - The International Society for Optical Engineering, 2008Konferensbidrag (Refereegranskat)
    Abstract [en]

    A novel all-optical frequency up-conversion method implementing microwave photonic filter in a radio-over-fiber (RoF) link is proposed and demonstrated. The electrooptical phase modulator, electrooptic intensity modulator in combination with 75-km single-mode fiber (SMF) is used to form the microwave photonic filter and fulfill the frequency up-conversion function at the same time. The technique requires large modulation index at the phase modulator, which simultaneously increases the efficiency of the frequency conversion. The proposed approach has been demonstrated both theoretically and experimentally.

  • 124. Pan, T.
    et al.
    Zhang, S.
    He, Sailing
    KTH, Skolan för elektro- och systemteknik (EES), Elektroteknisk teori och konstruktion. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP. South China Normal University (SCNU), China.
    Compact RFID tag antenna with circular polarization and embedded feed network for metallic objects2014Ingår i: IEEE Antennas and Wireless Propagation Letters, ISSN 1536-1225, E-ISSN 1548-5757, Vol. 13, s. 1271-1274, artikel-id 6843861Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A low-profile radio frequency identification (RFID) tag antenna is proposed with a compact size of 45 × 45~mm2 and circular polarization (CP) for metallic surfaces. A star-shaped slot is etched onto the antenna for the CP and antenna size reduction. A terminal-grounded L-shaped feedline is embedded in the etched slot to efficiently excite the wideband CP mode, complexly match the tag-antenna impedance, and further reduce the antenna size. The embedded feed structure also helps achieve a relatively higher gain, resulting in a longer reading range. The proposed antenna can cover the impedance bandwidth of 60 MHz (from 880 to 940 MHz) as well as the 3-dB CP bandwidth of 12 MHz (from 905 to 917 MHz). Further results demonstrate that the proposed tag antenna provides a stable reading range when mounted on metal plates of various sizes.

  • 125.
    Qian, Jun
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Fu, Tao
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Zhan, Qiuqiang
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    He, Sailing
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP. KTH, Skolan för elektro- och systemteknik (EES), Elektroteknisk teori och konstruktion.
    Using Some Nanoparticles as Contrast Agents for Optical Bioimaging2010Ingår i: IEEE Journal of Selected Topics in Quantum Electronics, ISSN 1077-260X, E-ISSN 1558-4542, Vol. 16, nr 3, s. 672-684Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The introduction of nanometric contrast agents to optical imaging is helpful for the understanding of some biological processes at the molecular level, as well as the development of diagnostic tools and therapies. Optical imaging agents such as gold nanorods (GNRs), quantum dots (QDs), and organically modified silica (ORMOSIL) nanoparticles can overcome many drawbacks of conventional agents, such as poor contrast, photobleaching, and low chemical and optical stability in biological environment. These nanoparticles can also be developed for absorbance, emission, and scattering in the near-IR region, which allows optical approaches for deep-tissue real-time imaging. The synthesis methods and optical properties of GNRs, QDs, and ORMOSIL nanoparticles are briefly introduced, and some of their applications in optical bioimaging are demonstrated. Specific targeting, "green" synthesis methods, and optical signal demodulation are also introduced.

  • 126.
    Qian, Jun
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Gharibi, Arash
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    He, Sailing
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Colloidal mesoporous silica nanoparticles with protoporphyrin IX encapsulated for photodynamic therapy2009Ingår i: Journal of Biomedical Optics, ISSN 1083-3668, E-ISSN 1560-2281, Vol. 14, nr 1Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Protoporphyrin IX (PpIX)-encapsulated mesoporous silica nanoparticles were synthesized, characterized, and utilized for photodynamic therapy (PDT) of cancer. Silica encapsulation is relatively transparent for activated light and can protect the PpIX against denaturation induced by the extreme bioenvironment. The mesoporous silica can also ensure that the encapsulated PpIX can be well-contacted with oxygen, stimulated, and released. PpIX-encapsulated colloidal mesoporous silica nanoparticles were uptaken by tumor cells in vitro, and the effect of photon-induced toxicity was demonstrated after comparison with some control experiments. The surface of PpIX-encapsulated silica nanoparticles can be grafted with appropriate functionalized groups and conjugated with certain biomolecules for specific targeting.

  • 127.
    Qian, Jun
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Jiang, Li
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Cai, Fuhong
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Wang, Dan
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    He, Sailing
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP. KTH, Skolan för elektro- och systemteknik (EES), Elektroteknisk teori och konstruktion.
    Fluorescence-surface enhanced Raman scattering co-functionalized gold nanorods as near-infrared probes for purely optical in vivo imaging2011Ingår i: Biomaterials, ISSN 0142-9612, E-ISSN 1878-5905, Vol. 32, nr 6, s. 1601-1610Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Gold nanorods (GNRs) have been widely used for bio-imaging. However, GNRs assisted optical in vivo deep tissue imaging is severely restricted due to signal attenuation, low contrast, complex process or low real-timing. To overcome these problems, we functionalized GNRs with both near-infrared (NIR) fluorescence and surface enhanced Raman scattering (SERS) and utilized these co-functionalized GNRs for purely optical in vivo imaging of live mice. Our proposed technology has the combined advantages of high real-timing, high imaging contrast and deep detection ability. The distribution and excretion of intravenously injected GNRs in deep tissues of live mice were observed in vivo for the first time through purely optical imaging. We also demonstrated successfully in vivo biomedical applications of the co-functionalized GNRs to sentinel lymph node (SLN) mapping and tumor targeting of mice. The present technology has great future potentials for disease diagnosis and clinical therapies.

  • 128.
    Qian, Jun
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Li, Xin
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Wei, Ming
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Gao, Xiangwei
    Xu, Zhengping
    He, Sailing
    KTH, Skolan för elektro- och systemteknik (EES), Elektroteknisk teori och konstruktion. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Bio-molecule-conjugated fluorescent organically modified silica nanoparticles as optical probes for cancer cell imaging2008Ingår i: Vol. 16, nr 24, s. 19568-19578Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Organically modified silica nanoparticles doped with Nile Red were synthesized and characterized. Silica encapsulation is relatively transparent for light and can protect hydrophobic Nile Red against denaturalization induced by the extreme bio-environment, making the entire nanoparticle hydrophilic and possess stable optical properties. The nanoparticles were conjugated with bio-molecules ( such as apo-transferrin and folic acid), and our in vitro experiments revealed that these functionalized nanoparticles can serve as effective optical probes for specific targeting of cancer cells. As a preliminary study for future in vivo animal experiment, ORMOSIL nanoparticles were further co-conjugated with polyethyleneglycol (PEG) and apo-transferrin and the conjugates were also very good for in vitro targeting of HeLa cells. These bio-molecule functionalized ORMOSIL nanoparticles may serve as a robust tool for early diagnosis/therapy of cancer and other diseases.

  • 129. Qian, Jun
    et al.
    Wang, Dan
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Cai, Fu-Hong
    Xi, Wang
    Peng, Li
    Zhu, Zhen-Feng
    He, Hao
    Hu, Ming-Lie
    He, Sailing
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Observation of Multiphoton-Induced Fluorescence from Graphene Oxide Nanoparticles and Applications in In Vivo Functional Bioimaging2012Ingår i: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 51, nr 42, s. 10570-10575Artikel i tidskrift (Refereegranskat)
  • 130.
    Qian, Jun
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Wang, Dan
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Cai, Fuhong
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Zhan, Qiuqiang
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Wang, Yalun
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    He, Sailing
    KTH, Skolan för elektro- och systemteknik (EES), Elektroteknisk teori och konstruktion. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Photosensitizer encapsulated organically modified silica nanoparticles for direct two-photon photodynamic therapy and In Vivo functional imaging2012Ingår i: Biomaterials, ISSN 0142-9612, E-ISSN 1878-5905, Vol. 33, nr 19, s. 4851-4860Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Nanoparticle-assisted two-photon imaging and near infrared (NIR) imaging are two important technologies in biophotonics research. In the present paper, organically modified silica (ORMOSIL) nanoparticles encapsulated with either PpIX (protoporphyrin IX) photosensitizers or IR-820 NIR fluorophores were synthesized and optically characterized. Using the former ORMOSIL nanoparticles, we showed: (i) direct excitation of the fluorescence of PpIX through its efficient two-photon absorption in the intracellular environment of tumor cells, and (ii) cytotoxicity towards tumor cells by PpIX under two-photon irradiation. The latter ORMOSIL nanoparticles can be used as efficient NIR fluorescent contrast agents for various types . in vivo animal imaging. We applied IR-820 doped ORMOSIL nanoparticles in . in vivo brain imaging of mice. We also demonstrated the applications of them to sentinel lymph node (SLN) mapping of mice. Finally, we showed that the nanoprobes could target the subcutaneously xenografted tumor of a mouse for long time observations. ORMOSIL nanoparticles have great potentials for disease diagnosis and clinical therapies.

  • 131.
    Qin, Haiyan
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Fu, Tao
    Centre for Optical and Electromagnetic Research, Zhejiang University.
    Yan, Ming
    Department of Life Science and Biomedical Engineering, Zhejiang.
    Ning, Zhijun
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    He, Sailing
    Joint Research Center of Photonics of the Royal Institute of Technology.
    Brismar, Hjalmar
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Cellens fysik.
    Ågren, Hans
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Highly stable and low toxic CdTe quantum dots synthesized via ahydrothermal method for cell imaging applicationsArtikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    Although biological applications of quantum dots (QDs) by now are widely recognized and reported, routine production of small-size water-soluble and stable QDs still remains a challenge. In the present work we highlight prospects offered by the hydrothermal method to synthesize water-soluble QDs. We illustrate the method by synthesizing CdTe QDs which process some outstanding properties like highly luminescent red emission and high stability over a wide pH range. Compared with those synthesized via the traditional aqueous method, we show that CdTe QDs synthesized via the hydrothermal method feature higher photostability and lower cytotoxicity. Based on such prepared CdTe QDs, luminescent QD-IgG bioprobes were produced to detect the breast cancer marker Her2 on the surface of MCF-7 cancer cells, indicating that such prepared QD systems are promising candidates for use as bioprobes.

  • 132.
    Qin, Shan
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Chen, Daru
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    A Simplified Model of Multi-wavelength Fibre Lasers based on Hybrid Fibre Raman and Erbium Fibre Amplifications2008Ingår i: AOE 2007: ASIA OPTICAL FIBER COMMUNICATION & OPTOELECTRONIC EXPOSITION & CONFERENCE, CONFERENCE PROCEEDINGS, SHENZHEN: AOE , 2008, s. 406-408Konferensbidrag (Refereegranskat)
    Abstract [en]

    A simplified model is established to explain the principle of stable multi-wavelength fibre laser based on hybrid fibre Raman and Erbium-doped fibre amplifications, the simulation results agree with the experimental results very well.

  • 133.
    Ruan, Zhichao
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    He, Sailing
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Open cavity formed by a photonic crystal with negative effective index of refraction2005Ingår i: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 30, nr 17, s. 2308-2310Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An open cavity formed by three 60 degrees wedges of a photonic crystal with negative effective index is designed and studied. The quality factor of the open cavity can be larger than 2000. The influence of the interface termination on the resonant frequency and the quality factor is studied.

  • 134.
    Ruan, Zhichao
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qui, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Enhanced Transmission through Periodic Arrays of Subwavelength Holes: The Role of Localized Waveguide Resonances2006Ingår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 96, nr 23, s. 233901-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    By using the rigid full-vectorial three-dimensional finite-difference time-domain method, we show that the enhanced transmission through a metallic film with a periodic array of subwavelength holes results from two different resonances: (i) localized waveguide resonances where each air hole can be considered as a section of metallic waveguide with both ends open to free space, forming a low-quality-factor resonator, and (ii) well-recognized surface plasmon resonances due to the periodicity. These two different resonances can be characterized from electromagnetic band structures in the structured metal film. In addition, we show that the shape effect in the enhanced transmission through the Au film with subwavelength holes is attributed to the localized waveguide resonance.

  • 135.
    Ruan, Zhichao
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qui, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Slow electromagnetic wave guided in subwavelength region along one-dimensional periodically structured metal surface2007Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 90, nr 20, s. 201906-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A perfect electric conductor surface with one-dimensional periodic rectangle holes is proposed as a surface-plasmon-like waveguide, where designed surface plasmon modes with very low group velocity are confined in a subwavelength region. It is shown that the half maximum of electric field intensity of the mode can be confined in a 0.20 lambda x0.10 lambda subwavelength region on the transversal plane and the group velocity approaches to zeros, where lambda is the wavelength in vacuum.

  • 136.
    Ruan, Zhichao
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Qui, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Xiao, Sanshui
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    He, Sailing
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Thylén, Lars
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Coupling between plane waves and Bloch waves in photonic crystals with negative refraction2005Ingår i: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 71, nr 4, s. 045111-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A comprehensive analysis of the coupling coefficients between plane waves in conventional dielectric media and Bloch waves of photonic crystals with effective negative refractions is performed by the layer Korringa-Kohn-Rostoker method. Employing the infinite layers refraction operator, semi-infinite size photonic crystals are considered. Some special coupling properties are discussed. In particular, the strong angular dependence of coupling coefficients is found even for an interface between air (n=1) and a photonic crystal with effective refractive index (n(eff)=-1). Thus, a negative refractive index defined by the radius of a circular equal-frequency contour does not guarantee an isotropic behavior.

  • 137.
    Shen, Jian Qi
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP. Zhejiang Univ, China.
    A Three-Dimensionally Isotropic and Perfectly Vacuum-Impedance-Matched Negative-Index Material2014Ingår i: Journal of the Physical Society of Japan, ISSN 0031-9015, E-ISSN 1347-4073, Vol. 83, nr 12, s. 124401-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A new scenario for realizing a gain left-handed atomic vapor medium based on both dressed-state mixed-parity transitions (for simultaneous electric-and magnetic-dipole resonance) and incoherently-pumped population transfer (for high gain amplification) in a four-level atomic system is suggested. Dressed-state assisted simultaneous electric-and magnetic-dipole allowed transitions in such a four-level atomic system (of, e.g., neutral alkali-metal atoms such as lithium and potassium atoms) are utilized for achieving negative refractive index with impedance perfectly matched to vacuum. The attractive features of the present scenario include: i) three-dimensionally isotropic negative indices; ii) incoherent-gain wave amplification; iii) perfect impedance matching to vacuum. All these important properties of the double-negative medium would have potential applications in designing some optical and photonic devices, including particularly subwavelength focusing system and negative-index superlens for perfect imaging.

  • 138.
    Shen, Jian Qi
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    A three-level dark state and double-control single-photon logic gates via quantum coherent control2012Ingår i: Annalen der Physik, ISSN 0003-3804, E-ISSN 1521-3889, Vol. 524, nr 2, s. 85-96Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Multilevel quantum coherence and its quantum-vacuum counterpart, where a three-level dark state is involved, are suggested in order to achieve new photonic and quantum optical applications. It is shown that such a three-level dark state in a four-level tripod-configuration atomic system consists of three lower levels, where constructive and destructive quantum interference between two control transitions (driven by two control fields) arises. We point out that the controllable optical response due to the double-control tunable quantum interference can be utilized to design some fascinating new photonic devices such as logic gates, photonic transistors and switches at quantum level. A single-photon two-input XOR logic gate (in which the incident gate photons are the individual light quanta of the two control fields) based on such an effect of optical switching control with an EIT (electromagnetically induced transparency) microcavity is suggested as an illustrative example of the application of the dark-state manipulation via the double-control quantum interference. The present work would open up possibility of new applications in both fundamental physics (e.g., field quantization and relevant quantum optical effects in artificial systems that can mimic atomic energy levels) and applied physics (e.g., photonic devices such as integrated optical circuits at quantum level).

  • 139.
    Shen, Jian Qi
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Automatic generation of nonadiabatic conditional geometric phase shift with a noncoplanar fibre system2006Ingår i: Physica Scripta, ISSN 0031-8949, E-ISSN 1402-4896, Vol. 73, nr 1, s. 79-83Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A new scheme for realizing a nonadiabatic conditional geometric phase shift via a noncoplanar (coiled) fibre system is presented. It is shown that the effective Hamiltonian that describes the interaction of polarized photons with a fibre medium is just the Wang-Matsumoto type of Hamiltonian. This, therefore, means that the coiled fibre system may be an ideal implementation for realizing the nonadiabatic geometric phase gates involved in the topological quantum computation. A remarkable feature of the present method is that it can automatically meet the conditions and requirements proposed in the Wang-Matsumoto nuclear magnetic resonance (NMR) scheme: specifically, (i) in the coiled fibre system, the dynamical phase of photon wavefunction caused by the interaction Hamiltonian automatically vanishes; (ii) the Wang-Matsumoto requirement for the parameters in the Wang-Matsumoto NMR Hamiltonian can be exactly satisfied automatically in such a fibre system; and (iii) the conditional initial state can be easily achieved by manipulating the initial wave vector of polarized photons.

  • 140.
    Shen, Jian Qi
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP. Zhejiang University, China.
    Canonical Acoustics and Its Application to Surface Acoustic Wave on Acoustic Metamaterials2016Ingår i: Journal of the Physical Society of Japan, ISSN 0031-9015, E-ISSN 1347-4073, Vol. 85, nr 8, artikel-id 084401Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In a conventional formalism of acoustics, acoustic pressure p and velocity field u are used for characterizing acoustic waves propagating inside elastic/acoustic materials. We shall treat some fundamental problems relevant to acoustic wave propagation alternatively by using canonical acoustics (a more concise and compact formalism of acoustic dynamics), in which an acoustic scalar potential and an acoustic vector potential (Phi, V), instead of the conventional acoustic field quantities such as acoustic pressure and velocity field (p, u) for characterizing acoustic waves, have been defined as the fundamental variables. The canonical formalism of the acoustic energy-momentum tensor is derived in terms of the acoustic potentials. Both the acoustic Hamiltonian density and the acoustic Lagrangian density have been defined, and based on this formulation, the acoustic wave quantization in a fluid is also developed. Such a formalism of acoustic potentials is employed to the problem of negative-mass-density assisted surface acoustic wave that is a highly localized surface bound state (an eigenstate of the acoustic wave equations). Since such a surface acoustic wave can be strongly confined to an interface between an acoustic metamaterial (e.g., fluid-solid composite structures with a negative dynamical mass density) and an ordinary material (with a positive mass density), it will give rise to an effect of acoustic field enhancement on the acoustic interface, and would have potential applications in acoustic device design for acoustic wave control.

  • 141.
    Shen, Jian Qi
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Coherent Manipulation of Optical Waves with Microwave Quantum Interference2013Ingår i: Journal of the Physical Society of Japan, ISSN 0031-9015, E-ISSN 1347-4073, Vol. 82, nr 4, s. 044001-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An experimentally feasible scheme of a four-level atomic system driven by two microwaves and one optical field is suggested in order to realize destructive and constructive quantum interference between the two microwave-driven transition pathways and hence to coherently manipulate the applied optical field. The destructive quantum interference can be switched to the constructive interference and vice versa if one tunes the intensity ratio of the two microwaves. Such an effect of tunable optical response based on microwave quantum interference may have some potential applications to the technique for designing new photonic and quantum optical devices, e. g., photonic logic gates, optical switches, and photonic transistors.

  • 142.
    Shen, Jian Qi
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP. Zhejiang University, China.
    Dispersion-sensitive surface plasmon wave assisted by incoherent gain2014Ingår i: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 329, s. 15-22Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A three-level system with pumped electric-dipole allowed transition for incoherent-gain negative permittivity is suggested in order to realize dispersion-sensitive surface plasmon wave. The present surface wave modes occurring at an interface between an incoherent-gain negative-permittivity "plasmonic" medium (e.g., a semiconductor-quantum-dot material) and an ordinary dielectric can be amplified due to population transfer in the three-level system of the negative-permittivity medium. The issues of complex phase constant and the attenuation coefficients in the adjacent media are considered for addressing the problem of loss compensation of surface plasmon wave. The effect of incoherent-gain amplification exhibited by the dispersion-sensitive surface plasmon wave can be utilized for designing new quantum optical and photonic devices, e.g., photonic transistors and logic gates.

  • 143.
    Shen, Jian Qi
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Double-negative atomic vapor assisted by two-photon quantum coherence2012Ingår i: Journal of the Optical Society of America. B, Optical physics, ISSN 0740-3224, E-ISSN 1520-8540, Vol. 29, nr 11, s. 3192-3200Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A scenario for realizing simultaneously negative permittivity and permeability of a two-photon quantum-coherent atomic vapor is suggested in order to achieve a left-handed atomic medium with a negative refractive index. One of the remarkable features of the present scheme is that it can lead to a controllable manipulation of the negative refractive index of the atomic vapor. Since the electric- and magnetic-dipole allowed transitions of atoms can be excited by visible and infrared lightwaves, the refractive index of the atomic vapor can exhibit its negative refractive index at optical and near-optical frequency bands. This may be a new scheme to fabricate a negatively refracting material based on the quantum optical approach. Such a three-dimensionally isotropic negative refractive index at visible and infrared wavelengths induced by the two-photon-resonant quantum coherence would find a potential application in fabrication of superlenses for perfect imaging and subwavelength focusing.

  • 144.
    Shen, Jian Qi
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Electric and magnetic dipole allowed transitions of atoms for three-dimensionally isotropic left handedness in a mixed atomic vapor2014Ingår i: Progress of Theoretical and Experimental Physics, ISSN 2050-3911, nr 3, s. 033A01-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Since previous negative-index atomic media based on quantum optical approaches are highly lossy, a proposal for realizing a three-dimensionally isotropic left-handed atomic vapor medium is suggested based on a mechanism of incoherent gain assisted atomic transitions. Two three-level atomic systems are utilized for producing simultaneously negative permittivity and negative permeability, respectively, in the same frequency band. We suggest that fine and hyperfine level transitions of atoms (e.g., a hyperfine level transition in a hydrogen atomic system and a fine level transition in an alkali-metal atomic system) would be applicable to realization of such a negatively refracting atomic vapor. The attractive features of the present scenario include: i) three-dimensionally isotropic negative indices; ii) incoherent gain wave amplification in the negative-index atomic vapor; iii) tunable negative indices depending upon external fields. Such a left-handed quantum optical medium can serve as a supporting substrate for lossy negative-index materials for loss compensation. It can also be used in designing new quantum optical and photonic devices (e.g., a subwavelength focusing system and a negative-index superlens for perfect imaging) because of its attractive properties of three-dimensional isotropy and high-gain wave amplification.

  • 145.
    Shen, Jian Qi
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP. Zhejiang Univ, Peoples R China.
    Electromagnetically-induced-transparency plasmonics: Quantum-interference-assisted tunable surface-plasmon-polariton resonance and excitation2014Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 90, nr 2, s. 023814-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An experimentally feasible configuration of a prism coupler with an electromagnetically-induced-transparency (EIT) medium layer, e.g., a semiconductor-quantum-dot (SQD) medium, deposited upon its prism base is suggested for generating tunable surface-plasmon-polariton resonance. Such surface-plasmon-polariton resonance and optical excitation of a surface plasmon wave can be manipulated by switchable quantum interference among SQD multilevel transitions driven by two external control fields. When an incident probe field is coupled into a surface plasmon wave excitation mode, the surface-plasmon-polariton (SPP) resonance at the interface between the SQD medium layer and the substrate will arise, and the quantum-coherently controllable reflection spectrum of the probe field on the prism base can be achieved. In this process, destructive and constructive quantum interference (determined by the intensity ratio of the two external control fields) in the SQD multilevel system plays a key role for achieving the tunable reflection spectrum. The EIT-based surface-plasmon-polariton resonance presented here will have three characteristics (some of them would be attractive): (i) switchable quantum interference exhibited by surface plasmon wave excitation, (ii) quantum-coherently controllable surface plasmon polaritons by external optical fields, (iii) surface wave sensitive to dispersion of the SQD quantum coherent medium. Such an effect of controllable optical response based on the quantum-interference switchable surface-plasmon-polariton resonance in the EIT-prism coupler may find some potential applications in design of new photonic and quantum optical devices.

  • 146.
    Shen, Jian Qi
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Fine-Structure Level Transition for Incoherent-Gain Isotropic Negative Permeability2013Ingår i: Journal of the Physical Society of Japan, ISSN 0031-9015, E-ISSN 1347-4073, Vol. 82, nr 12, s. 124003-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A three-dimensionally isotropic negative permeability of a neutral alkali-metal atomic medium, in which a fine-structure magnetic dipole-allowed transition in terahertz band is pumped for population transfer (and hence incoherent gain for negative permeability can be realized), is suggested based on quantum optical approach. The effects relevant to photonic resonance and quantum coherence are involved in the present quantum optical scheme of pumped magnetic-dipole allowed transition. The incoherent-gain assisted atomic medium (with fine-structure transition involved) may have some attractive features, e. g., three-dimensionally isotropic and homogeneous negative permeability for high-gain wave amplification at terahertz frequencies. Such a gain-assisted negative-permeability medium can be a candidate of magnetically resonant materials for artificial composite metamaterials, e.g., it may serve as a substrate of lossy negative-index materials for loss compensation or as a supporting medium for high-gain amplification of a TE-mode surface plasmon-like wave.

  • 147.
    Shen, Jian Qi
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Isotropic negatively-refracting atomic-vapor medium2007Ingår i: Modern physics letters B, ISSN 0217-9849, Vol. 21, nr 12, s. 717-728Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A new scenario to realize negative refraction with a photonic-resonant vapor material that can exhibit both electric and magnetic responses via multilevel quantum coherence is suggested. Compared with the previous method of artificial composite metamaterial, where the mechanism was considered by means of classical electromagnetic theory and the materials produced have anisotropic millimetre-scale composite structures, the present scheme suggested within the framework of quantum optics can be used to design and fabricate isotropic negatively-refracting materials with atomic-scale microscopic structure units. Such an advantage may lead to a potentially important application in the techniques of superlens and perfect imaging.

  • 148.
    Shen, Jian Qi
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Sensitive Optical Behavior in an Electromagnetically Induced Transparency Waveguide via Double-Control Quantum Interference2012Ingår i: Journal of the Physical Society of Japan, ISSN 0031-9015, E-ISSN 1347-4073, Vol. 81, nr 2, s. 024403-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A tripod-configuration four-level atomic system can exhibit nontrivial quantum destructive and constructive interference that could manipulate the optical response of an atomic vapour. It is shown that the tunable double-control electromagnetically induced transparency (EIT) would be controlled via the quantum interference between two control fields interacting with the present atomic system. If a metallic waveguide is filled with such a double-control four-level atomic vapour, the quantum vacuum mode structure in the present EIT waveguide would have a novel influence on the atomic spontaneous emission decay (and hence on the EIT optical behavior). As the waveguide dimension change (i.e., the change in length scale of cross section of waveguide) can vary the vacuum mode structure, which can lead to spontaneous emission enhancement or inhibition, the optical response (including absorption and transparency induced by the tunable double-control quantum destructive and constructive interference) of the atomic vapour in the waveguide is quite sensitive to small change in the waveguide dimension caused by external environmental factors (such as electric signal voltage, environmental temperature change and acoustic pressure). The sensitive optical response based on the mechanisms of both double-control quantum interference and quantum-vacuum manipulation presented here may have some potential applications to the technique for designing new photonic and quantum optical devices.

  • 149.
    Shen, Jian Qi
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Simultaneous negative permittivity and permeability in a coherent atomic vapour2007Ingår i: Chinese Physics (Beijing), ISSN 1009-1963, E-ISSN 1741-4199, Vol. 16, nr 7, s. 1976-1985Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A new quantum optical mechanism to realize simultaneously negative electric permittivity and magnetic permeability is suggested. In order to obtain a negative permeability, we choose a proper atomic configuration that can dramatically enhance the contribution of the magnetic- dipole allowed transition via the atomic phase coherence. It is shown that the atomic system chosen with proper optical parameters can give rise to striking electromagnetic responses (leading to a negative refractive index) and that the atomic vapour becomes a left-handed medium in an optical frequency band. Differing from the previous schemes of artificial composite metamaterials (based on classical electromagnetic theory) to achieve the left-handed materials, which consist of anisotropic millimetre- scale composite structure units, the left- handed atomic vapour presented here is isotropic and homogeneous at the atomic-scale level. Such an advantage may be valuable in realizing the superlens (and hence perfect image) with left- handed atomic vapour.

  • 150.
    Shen, Jian Qi
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Strong and weak confinement of parity-time-symmetric acoustic surface wave2014Ingår i: Europhysics letters, ISSN 0295-5075, E-ISSN 1286-4854, Vol. 105, nr 1, s. 17006-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A strongly confined acoustic surface wave is an acoustic eigenstate localized on an interface between an ordinary acoustic medium and an acoustic metamaterial with negative effective dynamical mass density. Here we show that there is a new unconventional acoustic surface wave sustained by a parity-time (PT)-symmetric acoustic interface system, in which the negative effective dynamical mass density is not required (but the effective mass densities of the two adjacent acoustic media should fulfill the parity-time symmetry). Such an acoustic parity-time symmetry in the effective mass density can be used to manipulate acoustic wave propagation, e. g., it can exhibit both weak and strong confinement of the unusual PT -symmetric acoustic surface wave, and can offer mechanisms for designing acoustic metamaterial devices that would have specific functions in controlling and guiding acoustic wave, including acoustic field enhancement and extraordinary acoustic transmission.

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