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  • 201. Xiao, Sanshui
    et al.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Theoretical study of the transmission properties of a metallic film with surface corrugations2007Ingår i: Journal of Optics. A, Pure and applied optics, ISSN 1464-4258, E-ISSN 1741-3567, Vol. 9, nr 4, s. 348-351Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Transmissions through a metallic film at near-infrared wavelengths with different surface corrugations on both sides are systemically studied. The calculations are performed by the three-dimensional finite-different time-domain method. Calculated results show that the transmissions are strongly dependent on the surface structures. Compared with other structures, the transmission for a film periodically drilled by cross air grooves are relatively larger. Transmission is enhanced more with symmetric conditions on both layers than the asymmetric case. The enhanced transmission can be explained by a competition between the absorption in the metal and enhanced transmission due to coupled surface plasmon resonance.

  • 202.
    Xiao, Sanshui
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Tidigare Institutioner, Mikroelektronik och informationsteknik, IMIT.
    Ruan, Z. C.
    He, Sailing
    KTH, Tidigare Institutioner, Teoretisk elektroteknik.
    Influence of the surface termination to the point imaging by a photonic crystal slab with negative refraction2004Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 85, nr 19, s. 4269-4271Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Point imaging by a photonic crystal slab due to the negative refraction is studied theoretically. By investigating the transfer function of the imaging system, the influence of the surface termination to the imaging quality is analyzed. It is shown that an appropriate surface termination is important for obtaining an image of good quality.

  • 203.
    Yan, Min
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO.
    Dai, Jin
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO.
    Lithography-free broadband visible light absorber based on a mono-layer of gold nanoparticles2014Ingår i: Journal of Optics, ISSN 2040-8978, E-ISSN 2040-8986, Vol. 16, nr 2, s. 025002-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We experimentally demonstrate a large area, optically opaque plasmonic absorber which can absorb 95% of visible light with an effective thickness of less than 150 nm. The absorber comprises, from top to bottom, a mono-layer of random gold nanoparticles, a dielectric spacer, and a bottom gold reflector. Reflectometry analyses show that its absorption is insensitive to the incidence's polarization or angle when the incident angle is less than 50 degrees. At a larger incident angle, reflection increases and absorption spectra differ for two polarizations. Numerical simulations based on a 3D finite-element method suggest that the high absorbance is due to collective efforts of dipolar particle resonances, most often strongly coupled and forming chain resonances, as well as coupling of light to the surface plasmon polariton, irrespective of the incidence's polarization, through the top-layer particles. Similar high absorptivity is also demonstrated with silver or aluminum as the bottom reflector. These highly efficient visible light absorbers can be potential candidates for a range of passive and active photonic applications, including solar-energy harvesting as well as producing artificial colors on a large scale.

  • 204.
    Yan, Min
    et al.
    Technical University of Denmark.
    Mortensen, Niels Asger
    Technical University of Denmark.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Engineering modes in optical fibers with metamaterial2009Ingår i: Frontiers of Optoelectronics in China, ISSN 1674-4128, Vol. 2, s. 153-158Artikel i tidskrift (Refereegranskat)
  • 205.
    Yan, Min
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Analysis of surface plasmon polariton using anisotropic finite elements2007Ingår i: IEEE Photonics Technology Letters, ISSN 1041-1135, E-ISSN 1941-0174, Vol. 19, nr 22, s. 1804-1806Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The anisotropic finite-element mesh is deployed in a vector finite-element method to numerically derive surface plasmon polaritons (SPPs) more efficiently. The superiority of the anisotropic mesh lies in the fact that SPP modes, predictably, have a sharp field variation in the surface-normal direction, whereas the variation along the surface-tangent direction is comparably gentle. A case study on metallic fiber shows that the employment of anisotropic finite elements reduces the problem size by a factor of seven.

  • 206.
    Yan, Min
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Compact optical waveguides based on hybrid index and surface-plasmon-polariton guidance mechanisms2007Ingår i: Active and Passive Electronic Components, ISSN 0882-7516, E-ISSN 1563-5031, Vol. 2007Artikel i tidskrift (Refereegranskat)
  • 207.
    Yan, Min
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Finite element study of metal-corner plasmon polariton waveguides2007Ingår i: Passive Components And Fiber-Based Devices Iv, Pts 1 And 2 / [ed] Li, MJ; Chem, J; Kawanishi, S; White, IH, 2007, Vol. 6781, s. 67812C-Konferensbidrag (Refereegranskat)
    Abstract [en]

    Surface plasmon poalriton (SPP) waveguides have the potential to bring technology revolutions in fields like photonic integration, optical sensing, and even deep sub-wavelength imaging. The peculiar guidance mechanism of such waveguides however imposes great challenges on our existing theoretical modeling tools. In this paper, the superiority of finite element method (FEM) is examined for deriving modes guided by realistic SPP waveguides. In consideration of the anisotropic field profiles of most SPP waveguides, we propose the deployment of anisotropic finite element mesh. The anisotropic finite mesh is found to be able to reduce the numerical problem size greatly. Among all SPP waveguides, we emphasis the importance of the metal-corner waveguides, including both V-channel and A-wedge waveguides. Such metal corners can be found in most SPP waveguides proposed or fabricated so far. The properties like dispersion and propagation loss etc are studied by using FEM. Subwavelength light guidance can be achieved by such corner waveguides when their angles are kept small enough. However their applicability in nanoscaled optical circuits is affected by high propagation loss. Loss reduction or introduction of metamaterial with gain is desired in order to obtain small mode field size as well as low loss.

  • 208.
    Yan, Min
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Guided plasmon polariton at 2D metal corners2007Ingår i: Journal of the Optical Society of America. B, Optical physics, ISSN 0740-3224, E-ISSN 1520-8540, Vol. 24, nr 9, s. 2333-2342Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We investigate the properties of plasmon polaritons guided by 2D monoangular metal corners with a vector finite-element method. Such corner waveguides in general include both V-channel- and A-wedge-type waveguides. The influences of both geometric parameters (i.e., corner angle, tip sharpness, etc.) and operating wavelength to the mode properties, such as effective mode index, loss, and mode field size, are inspected. It is noticed that both a smaller corner angle and a sharper corner tip help to better confine the mode field. The confinement of the V-channel waveguide is found to be especially sensitive to its angle, while the confinement of the A-wedge waveguide is affected about equally by its angle and tip sharpness. Almost all superior mode field confinement is realized at the expense of higher propagation loss for such waveguides. The chromatic dispersion of such waveguides is found to be adequate for applications in integrated optical circuits. The mode behaviors of realistic corner waveguides with finite sidewalls are also studied.

  • 209.
    Yan, Min
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Ruan, Zhichao
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Cylindrical invisibility cloak with simplified material parameters is inherently visible2007Ingår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 99, nr 23Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    It was proposed that perfect invisibility cloaks can be constructed for hiding objects from electromagnetic illumination [J. B. Pendry, D. Schurig, and D. R. Smith, Science 312, 1780 (2006)]. The cylindrical cloaks experimentally demonstrated [D. Schurig , Science 314, 977 (2006)] and theoretically proposed [W. Cai , Nat. Photon. 1, 224 (2007)] have however simplified material parameters in order to facilitate easier realization as well as to avoid infinities in optical constants. Here we show that the cylindrical cloaks with simplified material parameters inherently allow the zeroth-order cylindrical wave to pass through the cloak as if the cloak is made of a homogeneous isotropic medium, and thus visible. To all high-order cylindrical waves, our numerical simulation suggests that the simplified cloak inherits some properties of the ideal cloak, but finite scatterings exist.

  • 210.
    Yan, Min
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Ruan, Zhichao
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Scattering characteristics of simplified cylindrical invisibility cloaks2007Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 15, nr 26, s. 17772-17782Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The previously reported simplified cylindrical linear cloak is improved so that the cloak's outer surface is impedance-matched to free space. The scattering characteristics of the improved linear cloak is compared to the previous counterpart as well as the recently proposed simplified quadratic cloak derived from quadratic coordinate transformation. Significant improvement in invisibility performance is noticed for the improved linear cloak with respect to the previously proposed linear one. The improved linear cloak and the simplified quadratic cloak have comparable invisibility performances, except that the latter however has to fulfill a minimum shell thickness requirement (i.e. outer radius must be larger than twice of inner radius). When a thin cloak shell is desired, the improved linear cloak is much more superior than the other two versions of simplified cloaks.

  • 211.
    Yan, Min
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik.
    Thylen, Lars
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik.
    Layered metal-dielectric waveguide: subwavelength guidance, leveraged modulation sensitivity in mode index, and reversed mode ordering2011Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 19, nr 4, s. 3818-3824Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We describe a layered metal-dielectric waveguide, whose fundamental mode has an effective index as high as 7.35 at 1.55 mu m, enabling subwavelength spatial confinement. The loss is found to be reasonable in relation to the confinement. The indefinite dielectric tensor of the stratified metamaterial core generally leads to multimode operation of the waveguide, exhibiting a "reversed" mode ordering contrary to conventional waveguides. The waveguide features a strong leveraging in modal index change subject to a change of index in the dielectric layers, opening the design possibilities of very compact active electro-optic devices.

  • 212.
    Yan, Min
    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.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO.
    Parekh, D.
    Deep-subwavelength optical waveguides based on near-resonant surface plasmon polariton2008Ingår i: ECIO'08 Eindhoven - Proceedings of the 14th European Conference on Integrated Optics and Technical Exhibition, Contributed and Invited Papers, 2008, s. 209-212Konferensbidrag (Refereegranskat)
    Abstract [en]

    We discuss the feasibility of deploying two materials with close but opposite epsilon values for achieving deep-subwavelength surface plasmon polariton waveguides. In particular, waveguiding properties of a silver-silicon waveguide with a 25nm core size at 600nm wavelength are examined. Such waveguides potentially allows for ultrahigh-density optical integration.

  • 213.
    Yan, Min
    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.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Parekh, Devang
    Feasibility study of nanoscaled optical waveguide based on near-resonant surface plasmon polariton2008Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 16, nr 10, s. 7499-7507Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Currently subwavelength surface plasmon polariton (SPP) waveguides under intensive theoretical and experimental studies are mostly based on the geometrical singularity property of such waveguides. Typical examples include the metal-insulator-metal based waveguide and the metallic fiber. Both types of waveguides support a mode with divergent propagation constant as the waveguides' geometry (metal gap distance or fiber radius) shrinks to zero. Here we study an alternative way of achieving subwavelength confinement through deploying two materials with close but opposite epsilon values. The interface between such two materials supports a near-resonant SPP. By examining the relationship between mode propagation loss and the mode field size for both planar and fiber waveguides, we show that waveguides based on near-resonant SPP can be as attractive as those solely based on geometrical tailoring. We then explicitly study a silver and silicon based waveguide with a 25nm core size at 600nm wavelength, in its properties like single-mode condition, mode loss and group velocity. It is shown that loss values of both materials have to be decreased by similar to 1000 times in order to have 1dB/mu m propagation loss. Hence we point out the necessity of novel engineering of low-loss metamaterials, or introducing gain, for practical applications of such waveguides. Due to the relatively simple geometry, the proposed near-resonant SPP waveguides can be a potential candidate for building optical circuits with a density close to the electronic counterpart.

  • 214.
    Yan, Min
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik.
    Yan, Wei
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Cylindrical superlens by a coordinate transformation2008Ingår i: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 78, nr 12, s. 125113-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cylinder-shaped perfect lens deduced from the coordinate transformation method is proposed. The previously reported perfect slab lens is noticed to be a limiting form of the cylindrical lens when the inner radius approaches infinity with respect to the lens thickness. Connaturality between a cylindrical lens and a slab lens is affirmed by comparing their eigenfield transfer functions. We numerically confirm the subwavelength focusing capability of such a cylindrical lens with consideration of material imperfection. Compared to a slab lens, a cylindrical lens has several advantages, including finiteness in cross section and ability in lensing with magnification or demagnification. Immediate applications of such a cylindrical lens can be in high-resolution imaging and lithography technologies. In addition, its invisibility property suggests that it may be valuable for noninvasive electromagnetic probing.

  • 215.
    Yan, Min
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik.
    Yan, Wei
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik.
    Invisibility Cloaking by Coordinate Transformation2009Ingår i: Progress in optics, ISSN 0079-6638, Vol. 52, s. 261-304Artikel, forskningsöversikt (Refereegranskat)
  • 216.
    Yan, Wei
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Shen, L.
    High directive antenna based on metamaterial slab with zero permittivity2008Ingår i: Proceedings of SPIE - The International Society for Optical Engineering, 2008Konferensbidrag (Refereegranskat)
    Abstract [en]

    In the present paper, the properties of an antenna centred at a metamaterial slab with zero permittivity are investigated. It is analyzed that the antenna can achieve high directive performance. Its half power beam width (HPBW) decreases monotonically with the increase of the width of the slab. While the gain of such antenna can only be 0dB independent of the slab's width. When the permittivity deviates form zero to a little positive number, antenna can achieve high gain by choosing appropriate slab's width due to the transmission resonance. The effect of loss is also analyzed.

  • 217.
    Yan, Wei
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Ruan, Zhichao
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Yan, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Ideal Cylindrical Cloak and Influence of tiny perturbation2008Konferensbidrag (Refereegranskat)
    Abstract [en]

    The invisibility of cylindrical cloaks produced by arbitrary radially coordinate transformations is confirmed. The influence of a tiny geometrical perturbation at the inner boundary of the cloak is investigated. It is shown that a tiny perturbation would induce a noticeable field scattering, due to the slow convergence of the zero(th) order scattering coefficients. However, by choosing appropriate coordinate transformation functions, the noticeable scattering can be reduced. More interestingly, the slow convergence can be overcome drastically by putting a PEC (PMC) layer at the interior boundary of the cloak shell for TM (TE) mode.

  • 218.
    Yan, Wei
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Yan, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Achieving perfect imaging beyond passive and active obstacles by a transformed bilayer lens2009Ingår i: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 79, nr 16Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A bilayer lens is proposed based on transformation optics. It is shown that Pendry's perfect lens, perfect bilayer lens made of indefinite media, and the concept of compensated media are well unified under the scope of the proposed bilayer lens. Using this concept, we also demonstrate how one is able to achieve perfect imaging beyond passive objects or active sources which are present in front of the lens.

  • 219.
    Yan, Wei
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Yan, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Generalized compensated bilayer structure from the transformation optics perspective2009Ingår i: Journal of the Optical Society of America. B, Optical physics, ISSN 0740-3224, E-ISSN 1520-8540, Vol. 26, nr 12, s. B39-B49Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A systematic study on a generalized compensated bilayer structure is presented based on transformation optics. A compensated bilayer can be constructed through a general transformation plus a coordinate inversion based on a single layer in the electromagnetic (EM) space. Two outer boundaries of the obtained bilayer are mapped from the same surface. Such a bilayer has an optically zero volume (nihility) regardless of the material composition in the original single layer. This fact directly leads to the property of invariant scattering. A bilayer is also able to transfer the EM field from one side to the other with a scaling factor, which is determined by how the two side boundaries are mapped. For a properly chosen background, it is possible to achieve perfect optical imaging. Extensive numerical examples are given to demonstrate these identified properties and applications. Our study provides a more complete understanding of this class of transformation media by considering general geometries and arbitrary material properties.

  • 220.
    Yan, Wei
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Yan, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Generalized nihility media from transformation optics2011Ingår i: Journal of optics, ISSN 0150-536X, Vol. 13, nr 2Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Nihility media in the previous literature are usually understood as media with epsilon = mu = 0. Transformation optics opens a new perspective for capturing the essence of such media. From this perspective, we generalize the definition of nihility media as transformation media derived from volumeless geometrical elements. A volumeless geometrical elements can be either a point (P), a line (L), or a surface (S). Their corresponding transformation media are therefore called P-, L-, or S-type nihility media, respectively. The previous defined nihility media with epsilon = mu = 0 is a special case under the P-type nihility media. The constructions of nihility media by metamaterials are discussed. The eigenfields in different types of nihility media are derived. The interactions between an externally incident wave and a slab of nihility media in a free space background are analyzed. Furthermore, we discuss compensated bilayers composed of nihility media. It is shown that for a slab of P-type nihility media, a normally incident wave can perfectly transmit through, while all obliquely incident waves are completely blocked; for a slab made of L-type nihility media, both normally and obliquely incident waves can transmit with some reflections, which can be eliminated by adding a compensating L-type nihility media; for a slab of S-type nihility media, all field components can perfectly transmit through.

  • 221.
    Yan, Wei
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik.
    Yan, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik.
    Manipulation of light with alpha transformation media2011Ingår i: JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION, ISSN 1084-7529, Vol. 28, nr 6, s. 1058-1066Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A type of transformation media called a media is proposed by performing a direct transformation to the metric tensor of another kind of media, called seed media. Light rays in an alpha medium correlate to those in its seed medium through a simple displacement or rotation relation. Three types of commonly encountered anisotropic media are covered by the concept of alpha media: (1) media of slab shape, having continuous translational symmetry with respect to two Cartesian coordinate components; (2) media of cylindrical shape, having cylindrical rotational symmetry and continuous translational symmetry along the longitudinal direction; (3) media of spherical shape, having spherical rotational symmetry, with two principal axes along the symmetry directions, and with the material parameters in the same sign. Optical properties of such media can be effectively interpreted through recalling the properties of certain isotropic media, i.e., their seed media. Conversely, from simple isotropic media in which light trajectories are well known, one can design a media for manipulating light. Based on this fact, several optical devices, including frequency demultiplexers, beam splitters, focusing lenses, and radiation controllers, are designed and numerically verified. The famed invisibility cloak derived from a conventional coordinate transformation is revisited from the alpha media perspective.

  • 222.
    Yan, Wei
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Yan, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Manipulation of light with α transformation media2011Ingår i: Optical Society of America. Journal A: Optics, Image Science, and Vision, ISSN 1084-7529, E-ISSN 1520-8532, Vol. 28, nr 6, s. 1058-1066Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A type of transformation media called α media is proposed by performing a direct transformation to the metric tensor of another kind of media, called seed media. Light rays in an α medium correlate to those in its seed medium through a simple displacement or rotation relation. Three types of commonly encountered anisotropic media are covered by the concept of α media: (1) media of slab shape, having continuous translational symmetry with respect to two Cartesian coordinate components; (2) media of cylindrical shape, having cylindrical rotational symmetry and continuous translational symmetry along the longitudinal direction; (3) media of spherical shape, having spherical rotational symmetry, with two principal axes along the symmetry directions, and with the material parameters in the same sign. Optical properties of such media can be effectively interpreted through recalling the properties of certain isotropic media, i.e., their seed media. Conversely, from simple isotropic media in which light trajectories are well known, one can design α media for manipulating light. Based on this fact, several optical devices, including frequency demultiplexers, beam splitters, focusing lenses, and radiation controllers, are designed and numerically verified. The famed invisibility cloak derived from a conventional coordinate transformation is revisited from the α media perspective.

  • 223.
    Yan, Wei
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Yan, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Non-magnetic simplified cylindrical cloak with suppressed zeroth order scattering2008Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 93, nr 2Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A type of simplified cloaks with matched exterior boundaries is proposed. The cloak uses nonmagnetic material for the TM polarization and can function with a relatively thin thickness. It is shown that the zeroth order scattering of such cloak is dominant among all cylindrical scattering terms. A gap is added at the cloak's inner surface to eliminate the zeroth order scattering through the mechanism of scattering resonance. The reduction in scattering is relatively smooth, indicating that the proposed scattering reduction method has good tolerance to perturbations. Numerical simulations also confirm that the proposed structure has very low scattering.

  • 224.
    Yan, Wei
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Yan, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Ruan, Zhichao
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Coordinate transformations make perfect invisibility cloaks with arbitrary shape2008Ingår i: New Journal of Physics, ISSN 1367-2630, E-ISSN 1367-2630, Vol. 10Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    By investigating wave properties at cloak boundaries, invisibility cloaks with arbitrary shape constructed by general coordinate transformations are confirmed to be perfectly invisible to the external incident wave. The differences between line transformed cloaks and point transformed cloaks are discussed. The fields in the cloak medium are found analytically to be related to the fields in the original space via coordinate transformation functions. At the exterior boundary of the cloak, it is shown that no reflection is excited even though the permittivity and permeability do not always have a perfectly matched layer form, whereas at the inner boundary, no reflection is excited either, and in particular no field can penetrate into the cloaked region. However, for the inner boundary of any line transformed cloak, the permittivity and permeability in a specific tangential direction are always required to be infinitely large. Furthermore, the field discontinuity at the inner boundary always exists; the surface current is induced to make this discontinuity self-consistent. A point transformed cloak does not experience such problems. The tangential fields at the inner boundary are all zero, implying that no field discontinuity exists.

  • 225.
    Yan, Wei
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Yan, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Ruan, Zhichao
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Influence of geometrical perturbation at inner boundaries of invisibility cloaks2008Ingår i: Journal of the Optical Society of America A, ISSN 0740-3232, Vol. 25, nr 4, s. 968-973Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The influence of a geometrical perturbation (5 at the inner boundaries of both cylindrical and spherical invisibility cloaks on invisibility performance is presented. The analytic solutions for such influence in the case of the general coordinate transformation are given. We show that the cylindrical cloak is more sensitive than a spherical cloak to such a perturbation. The difference results from the different asymptotic properties of eigen-functions for the cylindrical and spherical wave equations. In particular, the zeroth-order scattering coefficient for a cylindrical cloak determined by -1/ln(delta) converges to zero very slowly. The noticeable scattering induced by the slow convergence speed can be decreased by choosing appropriate coordinate transformation functions. More interestingly, the slow convergence can be overcome dramatically by putting a PEC (PMC) layer at the interior boundary of the cloak shell for TM (TE) wave.

  • 226. Yang, Yuanqing
    et al.
    Li, Qiang
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO. State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China.
    Controlling the angular radiation of single emitters using dielectric patch nanoantennas2015Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 107, nr 3, artikel-id 031109Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Dielectric nanoantennas have generated much interest in recent years owing to their low loss and optically induced electric and magnetic resonances. In this paper, we investigate the coupling between a single emitter and dielectric patch nanoantennas. For the coupled system involving non-spherical structures, analytical Mie theory is no longer applicable. A semi-analytical model is proposed instead to interpret the coupling mechanism and the radiation characteristics of the system. Based on the presented model, we demonstrate that the angular emission of the single emitter can be not only enhanced but also rotated using the dielectric patch nanoantennas.

  • 227. Yang, Yuanqing
    et al.
    Zhao, Ding
    Gong, Hanmo
    Li, Qiang
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO.
    Plasmonic sectoral horn nanoantennas2014Ingår i: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 39, nr 11, s. 3204-3207Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this Letter, plasmonic sectoral horn nanoantennas working at near-infrared wavelength (1550 nm) have been investigated. We demonstrate that, although there are certain differences between the plasmonic and classical radio-frequency (RF) sectoral horn antennas, the plasmonic horns still possess a number of attractive features, like their RF counterparts, such as tunable high directivities, simplicity in fabrication, and ease of coupling to waveguides. As a specific application, we further show how to exploit these findings to optimize an optical wireless nanolink using the proposed horn nanoantennas, and obtain a 60-fold increase in the received power compared with the situation of matched dipole nanoantennas.

  • 228. Ye, T.
    et al.
    Lu, Y.
    Liu, F.
    Li, Q.
    Zhang, Ziyang
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Su, Y.
    160-Gb/s NRZ-to-PSK conversion using linear filtering in silicon ring resonators2008Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper proposes a scheme to achieve high-speed, all-optical non-retum-to-zero to phase-shift keying (NRZ-to-PSK) conversion by using the linear filtering in the silicon ring resonators. Simulation results are provided to verify the feasibility.

  • 229. Yu, Huakang
    et al.
    Fang, Wei
    Gu, Fuxing
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Yang, Zongyin
    Tong, Limin
    Longitudinal Lorentz force on a subwavelength-diameter optical fiber2011Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 83, nr 5, s. 053830-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We analyze the longitudinal Lorentz forces that a propagating continuous-wave light exerts on a subwavelength-diameter optical fiber. Our theoretical results show that, during the propagating process, the guided light exerts no net time-averaged force on the fiber. Via numerical simulation, we find a significant overall pull force of 0.4 pN/mW acting on a 450-nm-diam fiber tip at a wavelength of 980 nm due to the scattering of the end face and a calculated force distribution reveals the feature of a near-field accumulation. Our results may be helpful to the configuration of optomechanical components or devices based on these fibers.

  • 230. Yu, Huakang
    et al.
    Wang, Shanshan
    Fu, Jian
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Li, Yuhang
    Gu, Fuxing
    Tong, Limin
    Modeling bending losses of optical nanofibers or nanowires2009Ingår i: Applied Optics, ISSN 1559-128X, E-ISSN 2155-3165, Vol. 48, nr 22, s. 4365-4369Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Bending losses of nanofibers or nanowires with circular 90 degrees bends are simulated using a three-dimensional finite-difference time-domain (3D-FDTD) method. Dependences of bending losses on wavelength and polarization of guided light are investigated, as well as the diameters, refractive indices, and bending radii of nanowires. The acceptable bending losses (similar to 1 dB/90 degrees) predicted in glass, polymer, and semiconductor nanowires with bending radii down to micrometer level may offer valuable references for assembling highly compact photonic integrated circuits or devices with optical nanowires.

  • 231. Zhang, L.
    et al.
    Wang, T.
    Liu, Q.
    Hu, X.
    Wang, Jing
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Su, Y.
    Increasing the delay-bit rate product on silicon chip using Star-16QAM signal with high spectral efficiency2009Ingår i: Optical Transmission Systems, Switching, and Subsystems VII, 2009, s. 763204-Konferensbidrag (Refereegranskat)
    Abstract [en]

    We proposed and experimentally demonstrate the generation of a novel star-16QAM using a dual-parallel Mach-Zehnder modulator (DPMZM) followed by a phase modulator (PM). Coherent detection and off-line processing are used to recover constellation diagrams. We also study optical delay of a novel star-16QAM signal through a silicon microring resonator. Delay time of ∼ 30ps is observed by comparing the eye diagram of the star-16QAM signal on-resonance with that off-resonance.

  • 232. Zhang, L.
    et al.
    Wang, T.
    Liu, Q.
    Hu, X.
    Wang, Jing
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Su, Y.
    Increasing the delay-bit rate product on silicon chip using star-16QAM signal with high spectral efficiency2009Ingår i: 2009 Asia Communications and Photonics Conference and Exhibition, ACP 2009, 2009Konferensbidrag (Refereegranskat)
    Abstract [en]

    We experimentally demonstrate optical delay of a novel star-16QAM signal through a silicon microring resonator. Delay time of ∼ 30ps is observed by comparing the eye diagram of the star-16QAM signal on-resonance with that off-resonance.

  • 233.
    Zhang, Liyang
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Yan, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    The effect of transformation order on the invisibility performance of a practical cylindrical cloak2008Ingår i: Journal of Optics. A, Pure and applied optics, ISSN 1464-4258, E-ISSN 1741-3567, Vol. 10, nr 9Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A class of polynomial coordinate transformation functions with an arbitrary order number is used to design cylindrical invisibility cloaks. Since an ideal cylindrical cloak is inevitably unphysical at its inner boundary, our investigation involves the replacement of a thin layer of material at the cloak's inner surface by a homogeneous material layer. This approach effectively avoids the infinities in the material parameters, and at the same time produces practical near-ideal invisibility cloaks. The cloaks obtained are perfectly matched in impedance at the outer boundary. We quantitatively show the effect of the transformation order on the proposed cloak's scattering coefficients.

  • 234. Zhang, W.
    et al.
    Li, Q.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO.
    A plasmon ruler based on nanoscale photothermal effect2013Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 21, nr 1, s. 172-181Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The determination of nanoscale distances or distance changes necessitates a nanoscale ruler. In the present paper, distance dependence of particle temperature in an optically heated gold nanoparticle pair is quantitatively investigated to explore the possibility of creating a Plasmon ruler based on this effect. The two origins of the distance-dependence, i.e., electromagnetic coupling and thermal accumulative effect, are studied. For the particle temperature, a scaling behavior is found, and it suggests that the decay of particle temperature with the interparticle gap for different particle sizes follows a common exponential decay equation. This scaling behavior is qualitatively explained with a simple dipolar-coupling model combined with a point heat source interaction model. On the basis of this scaling behavior of absorption power, we further establish a plasmon ruler equation relating the particle temperature and the interparticle distance. Our findings can serve as an excellent guideline for designing and optimizing temperature-based plasmon rulers.

  • 235. Zhang, Weichun
    et al.
    Li, Qiang
    Meng, Lijun
    Zhao, Ding
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO. Zhejiang University, China.
    Universal scaling behavior of the temperature increase of a heat nanoparticle on a substrate2015Ingår i: JOURNAL OF NANOPHOTONICS, ISSN 1934-2608, Vol. 9, artikel-id 093046Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Knowledge of temperatures at the nanoscale is essential for studying and controlling the heat-induced local thermal responses. The temperature rise of a heated nanoparticle (NP) near the interface of two kinds of media with different thermal conductivities is numerically investigated. We find that the temperature rise becomes size independent if it is scaled by the temperature rise in the case where the particle-interface distance is zero and the distance is scaled by the equivalent radius of the NP. This universal scaling behavior can be understood with the principle of dimensional homogeneity. An empirical equation is retrieved to predict the actual particle temperature at a given position. Our results may benefit precise control of heat at the nanoscale with applications in plasmonic absorbers, immunotargeted photothermal cancer cell killing, etc.

  • 236.
    Zhang, Ziyang
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Andersson, Ulf
    KTH, Skolan för datavetenskap och kommunikation (CSC), Centra, Parallelldatorcentrum, PDC. KTH, Skolan för datavetenskap och kommunikation (CSC).
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Subwavelength-diameter Silica Wire and Photonic Crystal Waveguide Slow Light Coupling2007Ingår i: Active and Passive Electronic Components, ISSN 0882-7516, E-ISSN 1563-5031, Vol. 2007, s. 78602-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Counter-directional coupling between subwavelength-diameter silica wire and single-line-defect two-dimensional photonic crystal slab waveguide is studied numerically using parallel three-dimensional finite-different time-domain method. By modifying silica wire properties or engineering photonic crystal waveguide dispersion band, the coupling central wavelength can be moved to the slow light region and the coupling efficiency improves simultaneously. One design gives 82 peak power transmission from silica wire to photonic crystal waveguide over an interacting distance of 50 lattice constants. The group velocity is estimated as 1/35 of light speed in vacuum.

  • 237.
    Zhang, Ziyang
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Dainese, Matteo
    Replisaurus AB.
    Chacinski, Marek
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Wosinski, Lech
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    High-quality-factor micro-ring resonator in amorphous-silicon on insulator structure2008Ingår i: ECIO'08 Eindhoven - Proceedings of the 14th European Conference on Integrated Optics and Technical Exhibition, Contributed and Invited Papers, 2008, s. 329-332Konferensbidrag (Refereegranskat)
    Abstract [en]

    Micro-ring resonators have been fabricated in hydrogenated amorphous silicon on silica structure. The intrinsic quality factor is estimated as 56,000 and the notch depth is ̃ 30dB. The intrinsic loss per unit length is 15.3dB/cm, comparable to 9.16dB/cm in the single-crystalline silicon ring of the same geometry.

  • 238.
    Zhang, Ziyang
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Dainese, Matteo
    Replisaurus AB.
    Wosinski, Lech
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Resonance-splitting and enhanced notch depth in SOI ring resonators with mutual mode coupling2008Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 16, nr 7, s. 4621-4630Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Resonance-splitting and enhanced notch depth are experimentally demonstrated in micro-ring resonators on SOI platform as a result of the mutual mode coupling. This coupling can be generated either by the nanometer-scaled gratings along the ring sidewalls or by evanescent directional coupling between two concentric rings. The transmission spectra are fitted using the time-domain coupled mode analysis. Split-wavelength separation of 0.68 nm for the 5-mu m-radius ring, notch depth of 40 dB for the 10-mu m-radius ring, and intrinsic Q factor of 2.6 x 10(5) for the 20-mu m-radius ring are demonstrated. Notch depth improvement larger than 25dB has been reached in the 40-39-mu m-radius double-ring structure. The enhanced notch depth and increased modal area for the concentric rings might be promising advantages for bio-sensing applications.

  • 239.
    Zhang, Ziyang
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Dainese, Matteo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Wosinski, Lech
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Swillo, Marcin
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Two-dimensional photonic crystal surface-mode cavity in amorphous silicon-on-silica structure2007Konferensbidrag (Refereegranskat)
    Abstract [en]

    We have recently demonstrated an optical filter based on side coupling between silicon wire waveguide and two-dimensional photonic crystal surface-mode cavity. The design is first optimized numerically by parallel three-dimensional finite-different time-domain simulations. The device is then fabricated using electron-beam lithography and plasma etching on amorphous silicon-on-silica structure. The drop wavelength is observed around 1580nm. The extinction ratio of the filter is larger than 10dB and the intrinsic quality factor of the surface-mode cavity is approximately 2,000. The quality factor can be improved by optimization of fabrication procedures as well as cavity design to eliminate multi-mode behavior.

  • 240.
    Zhang, Ziyang
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Dainese, Matteo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Wosinski, Lech
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Swillo, Marcin
    PhoXtal Communications AB.
    Xiao, Sanshui
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Experimental demonstration of 2D photonic crystal surface cavity in amorphous silicon on silica structure2007Ingår i: OFC/NFOEC 2007 - Optical Fiber Communication and the National Fiber Optic Engineers Conference 2007, 2007, s. 4348573-Konferensbidrag (Refereegranskat)
    Abstract [en]

    Design, fabrication, and characterization of an optical filter based on side coupling between silicon wire waveguide and photonic crystal surface mode cavity in silicon on silica structure is presented for the 1550 nm wavelength spectral region.

  • 241.
    Zhang, Ziyang
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Dainese, Matteo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Wosinski, Lech
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Xiao, Sanshui
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Swillo, Marcin
    PhoXtal Communications AB.
    Andersson, Ulf
    KTH, Skolan för datavetenskap och kommunikation (CSC), Centra, Parallelldatorcentrum, PDC. KTH, Skolan för datavetenskap och kommunikation (CSC).
    Optical filter based on two-dimensional photonic crystal surface-mode cavity in amorphous silicon-on-silica structure2007Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 90, nr 4, s. 041108-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An optical filter based on side coupling between silicon wire waveguide and two-dimensional photonic crystal surface-mode cavity is presented. The design is optimized numerically by parallel three-dimensional finite-different time-domain simulations. The device is then fabricated on amorphous silicon-on-silica structure. The drop wavelength is observed around 1580 nm. The extinction ratio of the filter is larger than 10 dB and the intrinsic quality factor of the surface-mode cavity is approximately 2000.

  • 242.
    Zhang, Ziyang
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Li, Qiang
    Liu, Fangfei
    Ye, Tong
    Su, Yikai
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Wavelength Conversion in a Silicon Mode-split Micro-ring Resonator with 1G Data Rate2008Konferensbidrag (Refereegranskat)
    Abstract [en]

    We experimentally demonstrate the wavelength conversion based on free carrier dispersion effect induced by non-linear absorption in a silicon micro-ring resonator. The pump and signal wavelengths are set by the split resonances spaced by 0.4 nm induced by deformation in the coupling region. The results of 500 Mbps and 1Gbps are presented.

  • 243.
    Zhang, Ziyang
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Compact in-plane channel drop filter design using a single cavity with two degenerate modes in 2D photonic crystal slabs2005Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 13, nr 7, s. 2596-2604Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A compact in-plane channel drop filter design in 2D hexagonal lattice photonic crystal slabs is presented in this paper. The system consists of two photonic crystal waveguides and a single cavity with two degenerate modes. Both modes are able to confine light strongly in the vertical dimension and prove to couple equally into the waveguides. Three dimensional finite difference time domain simulations show that the quality factor is around 3,000. At resonance, power transferred to the drop waveguide is 78% and only 1.6% remains in the bus waveguide. We also show that by carefully tuning the drop waveguide boundary, light remaining in the bus can be further reduced to below 0.4% and thus the channel isolation is larger than 22dB.

  • 244.
    Zhang, Ziyang
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Coupled mode analysis of in-plane channel drop filters with resonant mirrors2005Ingår i: Photonics and Nanostructures-Fundamentals and Applications, ISSN 1569-4410, Vol. 3, nr 2-3, s. 84-89Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A channel drop filter system that consists of two waveguides and three cavities is studied. One cavity couples with both waveguides, while the other two work as resonant mirrors to reflect the selected channel back into the system. The operation of this configuration is analyzed, using coupled mode theory. The conditions to achieve 100% in-plane channel transfer are derived. A method to suppress the side lobes of reflection and backward drop is also proposed. The direct coupling between the cavities is not required. The analysis is verified by two-dimensional finite difference time domain simulations in 2D hexagonal photonic crystals.

  • 245.
    Zhang, Ziyang
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Fabrication tolerance tests on high-Q microcavities in 2D photonic crystal slabs2005Ingår i: Conference on Lasers and Electro-Optics Europe: Technical Digest, 2005Konferensbidrag (Refereegranskat)
  • 246.
    Zhang, Ziyang
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Influence of structural variations on high-Q microcavities in two-dimensional photonic crystal slabs2005Ingår i: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 30, nr 13, s. 1713-1715Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The influence of some critical structural variations in high-Q microcavities in two-dimensional photonic crystal slabs is investigated. All the cavities studied maintain a high Q in a wide range of structural variations, while the resonant frequencies shift on a relatively large scale when the structural variations are comparable to the physical sizes of the cavities.

  • 247.
    Zhang, Ziyang
    et al.
    KTH, Tidigare Institutioner, Mikroelektronik och informationsteknik, IMIT.
    Qiu, Min
    KTH, Tidigare Institutioner, Mikroelektronik och informationsteknik, IMIT.
    Small-volume waveguide-section high Q microcavities in 2D photonic crystal slabs2004Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 12, nr 17, s. 3988-3995Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A series of microcavities in 2D hexagonal lattice photonic crystal slabs are studied in this paper. The microcavities are small sections of a photonic crystal waveguide. Finite difference time domain simulations show that these cavities preserve high Q modes with similar geometrical parameters and field profile. Effective modal volume is reduced gradually in this series of microcavity modes while maintaining high quality factor. Vertical Q value larger than 106 is obtained for one of these cavity modes with effective modal volume around 5.40 cubic half wavelengths [(lambda/2n(slab))(3)]. Another cavity mode provides even smaller modal volume around 2.30 cubic half wavelengths, with vertical Q value exceeding 10(5).

  • 248.
    Zhang, Ziyang
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Andersson, Ulf
    KTH, Skolan för datavetenskap och kommunikation (CSC), Centra, Parallelldatorcentrum, PDC. KTH, Skolan för datavetenskap och kommunikation (CSC).
    Tong, Limin
    Department of Optical Engineering, Zhejiang University.
    Subwavelength-diameter Silica Wire for Light In-coupling to Silicon-based Waveguide2007Ingår i: Chinese optics letters, ISSN 1671-7694, Vol. 5, nr 10, s. 577-579Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Coupling between subwavelength-diameter silica wires and silicon-based waveguides is studied using the parallel three-dimensional (3D) finite-different time-domain method. Conventional butt-coupling to a silica-substrated silicon wire waveguide gives above 40% transmission at the wavelength range from 1300 to 1750 nm with good robustness against axial misalignments. Slow light can be generated by counter-directional coupling between a silica wire and a two-dimensional (2D) silicon photonic crystal slab waveguide. Through dispersion-band engineering, 82% transmission is achieved over a coupling distance of 50 lattice constants. The group velocity is estimated as 1/35 of the light speed in vacuum.

  • 249.
    Zhang, Ziyang
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Qui, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Coupled-mode analysis of a resonant channel drop filter using waveguides with mirror boundaries2006Ingår i: Journal of the Optical Society of America. B, Optical physics, ISSN 0740-3224, E-ISSN 1520-8540, Vol. 23, nr 1, s. 104-113Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The operation of resonant channel drop filters is analyzed using coupled-mode theory. The resonator is chosen to support a single standing-wave mode, and, in the ideal case, one can realize 100% in-plane channel transfer by properly applying mirror boundaries to the waveguides. The presence of the mirrors causes the resonant frequency to shift, and the system Q factor also changes accordingly. The two variables are related by a closed curve depending on the phase introduced by the reflection and wave propagation between the two ports. When one works on different regions of the curve, the system can be tuned to work at different resonant frequencies with minimum Q-factor variations or vice versa. The mirror can be frequency selective. The same single-mode cavity can be used as a resonant mirror to terminate the waveguide. The combined system is analyzed, and we find the conditions to achieve 100% channel transfer as well as to maintain a simple Lorentzian line shape of the transmission spectra. The analysis is verified by two-dimensional (2D) finite-difference time-domain simulations in 2D hexagonal photonic crystals.

  • 250. Zhao, Ding
    et al.
    Gong, Hanmo
    Yang, Yuanqing
    Li, Qiang
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Optik och Fotonik, OFO.
    Realization of an extraordinary transmission window for a seamless Ag film based on metal-insulator-metal structures2013Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 102, nr 20, s. 201109-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A polarization-sensitive, wide-angle operating antireflection coating based on a metal-insulator-metal structure is investigated. In both visible and near-infrared regions, it dramatically reduces the reflection and enhances the transmission through a seamless Ag film near a specifically designed frequency due to the surface plasmon resonance. By achieving above 70% transmission through a 20 nm-thickness Ag film theoretically, this antireflection coating is able to open an extraordinary transmission window for a metallic layer without any slits or holes.

23456 201 - 250 av 254
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