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  • 1. Abeywickrama, Sandu
    et al.
    Furdek, Marija
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Wong, Elaine
    Protecting core networks with dual-homing: A study on enhanced network availability, resource efficiency, and energy-savings2016In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 381, p. 327-335Article in journal (Refereed)
    Abstract [en]

    Core network survivability affects the reliability performance of telecommunication networks and remains one of the most important network design considerations. This paper critically examines the benefits arising from utilizing dual-homing in the optical access networks to provide resource-efficient protection against link and node failures in the optical core segment. Four novel, heuristic-based RWA algorithms that provide dedicated path protection in networks with dual-homing are proposed and studied. These algorithms protect against different failure scenarios (i.e. single link or node failures) and are implemented with different optimization objectives (i.e., minimization of wavelength usage and path length). Results obtained through simulations and comparison with baseline architectures indicate that exploiting dual-homed architecture in the access segment can bring significant improvements in terms of core network resource usage, connection availability, and power consumption.

  • 2.
    Almlöf, Jonas
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Quantum Electronics and Quantum Optics, QEO.
    Björk, Gunnar G. E.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Quantum Electronics and Quantum Optics, QEO.
    A short and efficient error correcting code for polarization coded photonic qubits in a dissipative channel2011In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 284, no 1, p. 550-554Article in journal (Refereed)
    Abstract [en]

    We propose a short and efficient non-degenerate quantum error correcting code that is adapted for qubits encoded on two orthogonal, single-photon states (e.g., horizontally and vertically polarized) subject to a dissipative channel. The proposed code draws its strength from the fact that it is adapted to the physical characteristics of the information-carrying basis states under the action of the channel. The code combines different energy manifolds and consists of only 3 spatio-temporal modes and on average 2 photons per code word.

  • 3. Beck, M.
    et al.
    Vogt, Ulrich
    Will, I.
    Liero, A.
    Stiel, H.
    Sandner, W.
    Wilheim, T.
    A pulse-train laser driven XUV source for picosecond pump-probe experiments in the water window2001In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 190, no 06-jan, p. 317-326Article in journal (Refereed)
    Abstract [en]

    We describe the development of a table top soft X-ray source based on a laser produced plasma. The plasma is produced by a Nd:YLF pulse-train laser which delivers pulse trains of up to 400 pulses each of about 25 ps duration, Number and energy of the micropulses are fully computer controlled adjustable for an optimum interaction with a rotating solid target. Spectral, spatial and temporal characteristics of the X-ray emission from Mylar and copper targets have been studied. A calibrated back-illuminated CCD camera together with a slit grating spectrograph were utilized for the measurement of the absolute soft X-ray photon fluxes. The temporal measurements were performed using a streak camera while the plasma size was measured with a zone plate. An application of the system in a X-ray absorption experiment is shown, The advantages of the system in view of possible optical pump and soft X-ray probe experiments will be discussed.

  • 4.
    Bjurshagen, Stefan
    et al.
    KTH, School of Engineering Sciences (SCI), Physics.
    Koch, R.
    Acreo AB, Kista.
    Laurell, Fredrik
    KTH, School of Engineering Sciences (SCI), Physics.
    Quasi-three-level Nd:YAG laser under diode pumping directly into the emitting level2006In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 261, no 1, p. 109-113Article in journal (Refereed)
    Abstract [en]

    We present theoretical and experimental investigations on ground-state direct pumping at 869 nm into the emitting level F-4(3/2) of end-pumped quasi-three-level Nd:YAG lasers operating at 946 nm. We have demonstrated, what we believe is for the first time, a Nd:YAG laser at 946 nm directly pumped by diodes and obtained 1.6 W of output power.

  • 5.
    Björk, Gunnar
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Quantum Electronics and Quantum Optics, QEO.
    Söderholm, Jonas
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Quantum Electronics and Quantum Optics, QEO.
    Sanchez-Soto, Luis L.
    Klimov, Andrei B.
    Ghiu, Iulia
    Marian, Paulina
    Marian, Tudor A.
    Quantum degrees of polarization2010In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 283, no 22, p. 4440-4447Article in journal (Refereed)
    Abstract [en]

    We discuss different proposals for the degree of polarization of quantum fields. The simplest approach, namely making a direct analogy with the classical description via the Stokes operators, is known to produce unsatisfactory results. Still, we argue that these operators and their properties should be basic for any measure of polarization. We compare alternative quantum degrees and put forth that they order various states differently. This is to be expected, since, despite being rooted in the Stokes operators, each of these measures only captures certain characteristics. Therefore, it is likely that several quantum degrees of polarization will coexist, each one having its specific domain of usefulness.

  • 6.
    Cai, Yangjian
    et al.
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    Ge, Di
    Analytical formula for a decentered elliptical Gaussian beam propagating in a turbulent atmosphere2007In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 271, no 2, p. 509-516Article in journal (Refereed)
    Abstract [en]

    Analytical formulas for the average intensity and decentered parameter of a decentered elliptical Gaussian beam (DEGB) propagating in a turbulent atmosphere are derived in a tensor form. The propagation properties of a DEGB in a turbulent atmosphere are investigated in detail, and found to be different from that in free space. Furthermore, as an application example, we investigate the propagation of a decentered elliptical flat-topped beam (DEFB) by expressing its electric field as a finite sum of DEGBs in a turbulent atmosphere. The properties of a DEGB or a DEFB in a turbulent atmosphere are closely related with the beam's parameters and the structure constant of the turbulent atmosphere.

  • 7.
    Cai, Yangjian
    et al.
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering. KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Zhang, Lei
    Propagation of a hollow Gaussian beam through a paraxial misaligned optical system2006In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 265, no 2, p. 607-615Article in journal (Refereed)
    Abstract [en]

    Based on the generalized diffraction integral formula for treating the propagation of a laser beam through a paraxial misaligned optical system in the cylindrical coordinate system, we obtain an analytical formula for a hollow Gaussian beam passing through a paraxial misaligned optical system. Furthermore, we also obtain the approximate analytical formula for a hollow Gaussian beam passing through a paraxial circularly apertured misaligned optical system by expanding the hard aperture function into a finite sum of complex Gaussian functions. As a numerical example, the propagation properties a hollow Gaussian beam through a misaligned thin lens are studied numerically.

  • 8. Chamaillard, K.
    et al.
    Friberg, Ari T.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Optics.
    Dainty, Chris
    Coherency matrix description for statistical linear regression of Stokes parameters in rough small-particle scattering2010In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 283, no 22, p. 4519-4524Article in journal (Refereed)
    Abstract [en]

    A statistical analysis of the Stokes parameters in light scattering by randomly rough small particles shows a linear regression law between the squares of the first two components I-s and Q(s) of the Stokes vector. While the coefficients of this linear regression contain physical characteristics of the particles, they cannot be directly interpreted in terms of the degree of polarization of the scattered field. We propose an interpretation of this relationship between the Stokes parameters on the basis of the general coherence-density matrix formalism. The link between the statistical regression results and the polarization properties of the stochastic scattered components of the field is established through the coherency matrix elements.

  • 9. Dai, D. X.
    et al.
    He, Sailing
    Novel ultrasmall Si-nanowire-based arrayed-waveguide grating interleaver with spirals2008In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 281, no 13, p. 3471-3475Article in journal (Refereed)
    Abstract [en]

    A novel layout is presented to achieve an ultrasmall arrayed-waveguide grating (AWG) interleaver based on Si-nanowire waveguides. Spiral waveguides are inserted in the middle of arrayed-waveguide to obtain a large lightpath (required for the ultra-high diffraction order) in a small occupied area. A designed ultrasmall AWG interleaver with a free spectral range of 0.8 nm has a total size of only about 73 mu m x 372 mu m (0.027 mm(2)).

  • 10. Dai, D. X.
    et al.
    Liu, L.
    He, Sailing
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    Analysis of integrated corner mirrors by using a wide-angle beam propagation method2006In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 260, no 2, p. 733-740Article in journal (Refereed)
  • 11. Dai, D. X.
    et al.
    Mei, W. Q.
    He, Sailing
    KTH, Superseded Departments, Electromagnetic Theory.
    Using a tapered MMI to flatten the passband of an AWG2003In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 219, no 01-6, p. 233-239Article in journal (Refereed)
  • 12. Dai, Daoxin
    et al.
    He, Sailing
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    Highly-sensitive sensor with large measurement range realized with two cascaded-microring resonators2007In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 279, no 1, p. 89-93Article in journal (Refereed)
  • 13.
    Dai, Daoxin
    et al.
    KTH, School of Electrical Engineering (EES), Centres, Alfvén Laboratory Centre for Space and Fusion Plasma Physics.
    He, Sailing
    KTH, School of Electrical Engineering (EES), Centres, Alfvén Laboratory Centre for Space and Fusion Plasma Physics.
    Reduction of multimode effects in an SOI-based etched diffraction grating demultiplexer2005In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 247, no 4-6, p. 281-290Article in journal (Refereed)
    Abstract [en]

    Multimode effects in the free propagation region (FPR) of a silicon-on-insulator (SOI)-based etched diffraction grating (EDG) demultiplexer are analyzed. In a conventional design, the power coupled to the higher order modes is considerable, which introduces a significant excess loss and crosstalk. It is shown that the multimode effects in an SOI EDG demultiplexer are much more detrimental than in an arrayed waveguide grating demultiplexer. Several methods for reducing the multimode effects are discussed. In particular, a laterally tapered structure between the FPR and the input/output waveguides is proposed as a simple and effective method for reducing the power coupled to the higher order modes and consequently reducing the multimode effects. The taper width is optimized to minimize the crosstalk.

  • 14.
    Dai, Daoxin
    et al.
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering. KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Liu, Liu
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT. KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    He, Sailing
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering. KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Three-dimensional hybrid modeling based on a beam propagation method and a diffraction formula for an AWG demultiplexer2007In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 270, no 2, p. 195-202Article in journal (Refereed)
    Abstract [en]

    An efficient and accurate three-dimensional (3D) hybrid modeling, which combines a 3D beam propagation method (BPM) and the two-dimensional (2D) Kirchhoff-Huygens diffraction formula, is developed to simulate the field propagation in an arrayed waveguide grating (AWG) dernultiplexer. The 2D Kirchhoff-Huygens diffraction formula is used for the simulation of the light propagation in the free propagation regions (FPRs). A 3D BPM in a polar coordinate system is used to simulate the light propagation in the transition region between the input FPR and the arrayed waveguides so that the coupling coefficients for the arrayed waveguides are calculated conveniently and accurately. For the simulation in the transition region between the arrayed waveguides and the output FPR, only the central arrayed waveguide and several adjacent ones are needed in the computational window of a standard BPM and thus the computation efficiency is improved. Finally, a flat-top AWG is designed and fabricated to verify the reliability of the present simulation method. The calculated and measured spectral responses are in a good agreement.

  • 15.
    Dainese, Matteo
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Swillo, Marcin
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Wosinski, Lech
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Directional coupler wavelength selective filter based on dispersive  Bragg Reflection Waveguide2006In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 260, no 2, p. 514-521Article in journal (Refereed)
    Abstract [en]

    A new type of wavelength selective filter, based on high differential dispersion between two coupled waveguides, is presented. The Bragg Reflection Waveguide displays high effective refractive index dispersion, due to the interaction of the guided mode with the two confining Bragg reflectors. When coupled with a weakly guided buried channel silica waveguide, a very narrow bandwidth filter (< 1 nm) can be easily produced, in a shorter length, with respect to directional couplers made with standard step index channel waveguides. The complete design methodology, fabrication and characterization are presented.

  • 16.
    Denker, Boris
    et al.
    A.M.Prokhorov General Physics Institute, Moscow.
    Galagan, Boris
    A.M.Prokhorov General Physics Institute, Moscow.
    Osiko, V.
    A.M.Prokhorov General Physics Institute, Moscow.
    Sverchkov, S.
    A.M.Prokhorov General Physics Institute, Moscow.
    Balbashov, A.
    Moscow Power Engineering Institute.
    Hellström, Jonas
    KTH, School of Engineering Sciences (SCI), Physics.
    Pasiskevicius, Valdas
    KTH, School of Engineering Sciences (SCI), Physics.
    Laurell, Fredrik
    KTH, School of Engineering Sciences (SCI), Physics.
    Yb3+,Er3+:YAG at high temperatures: energy transfer and spectroscopic properties2007In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 271, no 1, p. 142-147Article in journal (Refereed)
    Abstract [en]

    Energy transfer and spectroscopic properties at high temperatures have been investigated in Er,Yb:YAG crystals. It is shown that at elevated temperatures around 600-800 degrees C these characteristics become similar to those in the efficient 1.5 mu m laser medium - Er,Yb-doped phosphate glasses. (c) 2006 Elsevier B.V. All rights reserved.

  • 17.
    Dong, Hui
    et al.
    Nanyang Techbological University, Singapore.
    Shum, Ping
    Nanyang Techbological University, Singapore.
    Yan, Min
    Nanyang Techbological University, Singapore.
    Zhou, Junqiang
    Ning, Guoxiang
    Gong, Yandong
    Wu, Chongqing
    Measurement of Mueller matrix for an optical fiber system with birefringence and polarization-dependent loss or gain2007In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 274, no 1, p. 116-113Article in journal (Refereed)
    Abstract [en]

    In an optical fiber system with both birefringence and polarization-dependent loss or gain (PDL/G), a set of input polarization states and their corresponding outputs are deduced to fulfill some general relationships in Stokes space, by considering the fact that the Mueller matrix of such an optical fiber system meets Lorentz transformation. Then, it can be proven that the minimum number of input polarization states is three for an explicit determination of such a Mueller matrix and no independent input parameter is redundant. Based on the theoretical findings, a general and simple approach is proposed to measure the Mueller matrix. The requirements regarding the choices of three inputs are presented for achieving optimum measurement stability and accuracy. Experimental results on an optical fiber system, formed by two 10-km long single-mode fibers with an optical isolator in between, show excellent agreement with the theory.

  • 18. Drummond, Miguel V.
    et al.
    Nogueira, Rogerio N.
    Violas, Manuel
    Monteiro, Paulo P.
    Sterner, Carola
    KTH, School of Information and Communication Technology (ICT), Centres, Kista Photonics Research Center, KPRC.
    Fonjallaz, Pierre-Yves
    KTH, School of Information and Communication Technology (ICT), Centres, Kista Photonics Research Center, KPRC.
    All-optical generation of 40 Gb/s single sideband signals using a fiber Bragg grating2010In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 283, no 12, p. 2492-2495Article in journal (Refereed)
    Abstract [en]

    In this work, we demonstrate a reliable all-optical technique for performing optical double sideband (ODSB) to single sideband (OSSB) format conversion of a 40 Gb/s non-return-to-zero signal. It is based on the optimization of a detuned optical filter, which was implemented on a fiber Bragg grating (FBG) with a complex apodization profile. An OSSB signal with negligible distortion was obtained, as the FBG presented a nearly ideal frequency response. Higher tolerance to chromatic dispersion enabled by the OSSB signal in comparison to the ODSB signal was demonstrated on both simulation and experimental results. (C) 2010 Elsevier B.V. All rights reserved.

  • 19.
    Friberg, Ari T.
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Turunen, Jari
    Univ Eastern Finland, Dept Math & Phys, FI-80101 Joensuu, Finland..
    Optics communications special issue "electromagnetic coherence and polarization"2010In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 283, no 22, p. 4423-4426Article in journal (Other academic)
  • 20.
    Friberg, Ari T.
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Visser, T. D.
    Wang, W.
    Wolf, E.
    Focal shifts of converging diffracted waves of any state of spatial coherence2001In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 196, no 06-jan, p. 1-7Article in journal (Refereed)
    Abstract [en]

    We analyze the focusing of wave fields of any state of coherence by systems with low Fresnel numbers. We study the optical intensity on the axis in the focal region. The dependence of the focal shift and of the maximum on-axis intensity on the state of coherence is examined for some model fields.

  • 21. Fu, H. Y.
    et al.
    Ou, H. Y.
    Zhu, K.
    Remb, E.
    He, Sailing
    A tunable and reconfigurable microwave photonic filter based on two cascaded modulators and a dispersive medium2008In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 281, no 22, p. 5550-5554Article in journal (Refereed)
    Abstract [en]

    A novel tunable and reconfigurable microwave photonic filter based on two cascaded modulators and a dispersive medium is proposed, theoretically discussed and experimentally demonstrated. A single-wavelength LD and a modulator (either a Mach-Zehnder modulator or a phase modulator which can avoid the do bias drift problem) are used to obtain a multi-wavelength optical source. By adjusting the modulation frequency and the bias voltage on the modulators, the wavelength spacing and the relative amplitude of the optical tones change, thus making the filter tunable and reconfigurable. The experimental results show that the proposed filters have good tunability and reconfigurability and the mainlobe-to-sidelobe ratio of around 25 dB is achieved.

  • 22. Gong, Y.
    et al.
    Yang, B.
    Zhang, D.
    Hong, X.
    Lu, Y.
    He, Sailing
    KTH, School of Electrical Engineering and Computer Science (EECS), Electromagnetic Engineering. South China Normal University, Guangzhou, China.
    Chen, Jiajia
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab). South China Normal University, Guangzhou, China.
    Crosstalk-aware multiple-AWG based optical interconnects for datacenter networks2018In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 426, p. 151-157Article in journal (Refereed)
    Abstract [en]

    This paper proposes a crosstalk-aware passive optical interconnect architecture based on multiple arrayed waveguide gratings (AWGs). With two-stage cascaded AWGs, it can realize the communications not only within but also among the clusters for large-scale datacenters. To overcome serious crosstalk in multiple-AWG based optical interconnects, crosstalk suppression schemes are proposed. Proof-of-concept experiments are carried out to verify the necessity and feasibility of the proposed crosstalk suppression schemes for multiple-AWG based optical interconnects.

  • 23. Han, Zhanghua
    et al.
    He, Sailing
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    Multimode interference effect in plasmonic subwavelength waveguides and an ultra-compact power splitter2007In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 278, no 1, p. 199-203Article in journal (Refereed)
  • 24. Hong, Y.
    et al.
    Hong, Xuezhi
    KTH, School of Information and Communication Technology (ICT).
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    He, Sailing
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    Elastic all-optical multi-hop interconnection in data centers with adaptive spectrum allocation2017In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 383, p. 478-484Article in journal (Refereed)
    Abstract [en]

    In this paper, a novel flex-grid all-optical interconnect scheme that supports transparent multi-hop connections in data centers is proposed. An inter-rack all-optical multi-hop connection is realized with an optical loop employed at flex-grid wavelength selective switches (WSSs) in an intermediate rack rather than by relaying through optical-electric-optical (O-E-O) conversions. Compared with the conventional O-E-O based approach, the proposed all-optical scheme is able to off-load the traffic at intermediate racks, leading to a reduction of the power consumption and cost. The transmission performance of the proposed flex-grid multi-hop all-optical interconnect scheme with various modulation formats, including both coherently detected and directly detected approaches, are investigated by Monte-Carlo simulations. To enhance the spectrum efficiency (SE), number-of-hop adaptive bandwidth allocation is introduced. Numerical results show that the SE can be improved by up to 33.3% at 40 Gbps, and by up to 25% at 100 Gbps. The impact of parameters, such as targeted bit error rate (BER) level and insertion loss of components, on the transmission performance of the proposed approach are also explored. The results show that the maximum SE improvement of the adaptive approach over the non-adaptive one is enhanced with the decrease of the targeted BER levels and the component insertion loss.

  • 25.
    Islam, A. B. M. Hamidul
    et al.
    KTH, School of Information and Communication Technology (ICT).
    Westergren, Urban
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics.
    Very low input voltage cascaded travelling wave electroabsorption modulator (CTWEAM) for more than 100 Gbps2013In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 297, p. 43-47Article in journal (Refereed)
    Abstract [en]

    This paper presents the large signal modeling and simulation of two segmented travelling wave electroabsorption modulators (TWEAM) as a cascaded TWEAM (CTWEAM) structure. It will be demonstrated that a mushroom shaped mesa structure with low series resistance (0.69 Omega-mm) will have 3 dB bandwidth more than sufficient for 100 Gbps operation. For a CTWEAM device with 990 lam active segment length, 1.1 V bias voltage and only 0.4 V peak-to-peak (Vp-p) modulating voltage has a bandwidth of 110 GHz, extinction ratio >4 dB and flat frequency response. This device would be an attractive candidate for short distance optical fiber communication as well as long distance telecommunication at 0.4 Vp-p and 1 Vp-p input RF signal, respectively.

  • 26.
    Jalali-Roudsar, Amir Abbas
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Friberg, Ari T.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Faraday rotation in two-dimensional magneto-optic photonic crystal2005In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 253, no 1-3, p. 145-150Article in journal (Refereed)
    Abstract [en]

    We study the enhancement of Faraday rotation in a two-dimensional square-lattice magneto-optic photonic crystal at optical wavelengths. We show that on incidence of a TM plane wave onto the magneto-optic photonic crystal, high TM-TE mode conversion takes place in the transmission bands of TM and TE fields. The photonic crystal structure increases the average wave path length, which in turn leads to a growth in the polarization rotation. We also show that associated with this phenomenon is a widening of the photonic crystal transmission band.

  • 27.
    Jaroszewicz, Zbigniew
    et al.
    Institute of Applied Optics, Warsaw.
    Burvall, Anna
    National University of Ireland, Galway.
    Goncharov, Alexander
    National University of Ireland, Galway.
    Kolacz, Katarzyna
    Institute of Applied Optics, Warsaw.
    Spheric long-focal-depth lens: a comment2008In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 281, no 19, p. 4849-4850Article in journal (Refereed)
  • 28.
    Johansson, Sandra
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.
    Pasiskevicius, Valdas
    KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.
    Laurell, Fredrik
    KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.
    Hansson, Renee
    Ekvall, Katrin
    KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.
    Laser diode beam shaping with GRIN lenses using the twisted beam approach and its application in pumping of a solid-state laser2007In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 274, no 2, p. 403-406Article in journal (Refereed)
    Abstract [en]

    We report a novel beam shaping method for laser diodes based on the concept of twisted Gaussian Schell-model beams using GRIN lenses. This method enables a more symmetric pump as well as a compact setup for pumping of solid-state lasers. In the experiment with a standard 2 W diode, the beam quality factors in the two orthogonal directions were equalized to M-x(2) approximate to 24 and M-y(2) approximate to 18, respectively, which pumped an intra-cavity frequency-doubled Nd:YAG laser at 946 run with an output of 28 mW at 473 nm.

  • 29. Karlsson, G.
    et al.
    Pasiskevicius, Valdas
    KTH, Superseded Departments, Physics.
    Laurell, Fredrik
    KTH, Superseded Departments, Physics.
    Tellefsen, J. A.
    Q-switching of an Er-Yb: glass microchip laser using an acousto-optical modulator2003In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 217, no 06-jan, p. 317-324Article in journal (Refereed)
    Abstract [en]

    We present a compact Q-switched Er-Yb:glass microchip laser operating at the wavelength of 1.535 mum using an acousto-optical modulator. A Q-switched peak power of 325 W with a pulse-duration of 38 ns and a pulse-to-pulse jitter of less then 10 ns was achieved. Well-controlled pulses were obtained for repetition rates up to 10 kHz while the maximum pulse energy was 12 muJ. The experimental results are compared with theoretical analysis, which shows how to optimize the laser as well as fundamental limitations.

  • 30.
    Khan, Salman Naeem
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Dai, Daoxin
    KTH, School of Electrical Engineering (EES), Centres, Alfvén Laboratory Centre for Space and Fusion Plasma Physics. KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Liu, Liu Ming
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Wosinski, Lech
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics.
    He, Sailing
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Optimal design for a flat-top AWG demultiplexer by using a fast calculation method based on a Gaussian beam approximation2006In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 262, no 2, p. 175-179Article in journal (Refereed)
    Abstract [en]

    Passband broadening of an AWG (array waveguide grating) demultiplexer with an MMI (multimode interference) coupler connected at the end of a tapered input waveguide is considered. An explicit formula based on the field propagation of an approximate Hermit-Gaussian beam is used to calculate quickly and reliably the spectral response of the AWG demultiplexer. The widths of the input waveguide, the output waveguides and the MMI coupler are optimized. The optimal design is verified with the experimental measurement.

  • 31. Lee, Hwang Woon
    et al.
    Lee, Kwangjin
    Cho, Sunghun
    Anthony, John Kiran
    Lee, Soonil
    Lim, Hanjo
    Kim, Kihong
    Pasiskevicius, Valdas
    KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.
    Rotermund, Fabian
    Evaluation of the third-order optical nonlinearity of Au:SiO2 nanocomposites in the off-resonant spectral region2013In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 286, p. 347-352Article in journal (Refereed)
    Abstract [en]

    The third-order nonlinear optical susceptibility (chi((3))) of Au:SiO2 nanocomposite films with different Au particle sizes was measured to be on the order of 10(-10) esu to 10(-9) esu in the off-resonant spectral region, and the particle size-dependent behavior of chi((3)) was observed. The results were found to deviate substantially from those of the conventional Maxwell-Garnet theory. By adapting the modified invariant imbedding method, which takes into account the effect of interparticle interactions on the nonlinear response, we successfully explain the enhanced third-order nonlinear susceptibility of metal-dielectric nanocomposites at off-resonant wavelengths.

  • 32. Li, J. S.
    et al.
    He, Sailing
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    Broadband traveling-wave modulator based on Si2N2O substrate2005In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 254, no 04-6, p. 236-241Article in journal (Refereed)
  • 33.
    Lin, Rui
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS. Huazhong University of SciandTech (HUST), China.
    Feng, Z.
    Tang, M.
    Wang, R.
    Fu, S.
    Shum, P.
    Liu, D.
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS. South China Normal University, China.
    Palm-shaped spectrum generation for dual-band millimeter wave and baseband signals over fiber2016In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 367, p. 137-143Article in journal (Refereed)
    Abstract [en]

    In order to offer abundant available bandwidth for radio access networks satisfying future 5G requirements on capacity, this paper proposes a simple and cost-effective palm-shaped spectrum generation scheme that can be used for high capacity radio over fiber (RoF) system. The proposed scheme can simultaneously generate an optical carrier used for upstream and two bands of millimeter wave (MMW) that are capable of carrying different downstream data. The experiment results show that the proposed palm-shaped spectrum generation scheme outperforms optical frequency comb (OFC) based multi-band MMW generation in terms of upstream transmission performance. Furthermore, simulation is carried out with different dual-band MMW configurations to verify the feasibility of using the proposed spectrum generation scheme in the RoF system.

  • 34.
    Lin, Rui
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab). Huazhong University of Sci&Tech (HUST), China.
    Szczerba, K.
    Agrell, E.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Tang, M.
    Liu, D.
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Scalability analysis methodology for passive optical interconnects in data center networks using PAM2017In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 403, p. 283-289Article in journal (Refereed)
    Abstract [en]

    A framework is developed for modeling the fundamental impairments in optical datacenter interconnects, i.e., the power loss and the receiver noises. This framework makes it possible, to analyze the trade-offs between data rates, modulation order, and number of ports that can be supported in optical interconnect architectures, while guaranteeing that the required signal-to-noise ratios are satisfied. To the best of our knowledge, this important assessment methodology is not yet available. As a case study, the trade-offs are investigated for three coupler-based top-of-rack interconnect architectures, which suffer from serious insertion loss. The results show that using single-port transceivers with 10 GHz bandwidth, avalanche photodiode detectors, and quadratical pulse amplitude modulation, more than 500 ports can be supported.

  • 35. Lindberg, J.
    et al.
    Setala, T.
    Kaivola, M.
    Friberg, Ari T.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Optics.
    Coherence and polarization properties of a three-dimensional, primary, quasi-homogeneous, and isotropic source and its far field2010In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 283, no 22, p. 4452-4456Article in journal (Refereed)
    Abstract [en]

    We study the spatial coherence properties of a three-dimensional, primary, quasi-homogeneous, and isotropic source and the far field that it generates. We assess the spectrum, degree of polarization, electromagnetic degree of coherence, and effective degree of coherence of the source and of the far field. We also demonstrate the formalism for a spherical Gaussian Schell-model current source. The polarization properties of light are fully accounted for in the analysis, and it is found that certain results pertaining to scalar coherence theory are reproduced also within the electromagnetic treatment.

  • 36.
    Liu, Liu
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Han, Z.
    Forsberg, Erik
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Ultra-compact Directional Couplers and Mach-Zehnder Interferometers employing Surface Plasmon Polaritons2005In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 259, no 2, p. 690-695Article in journal (Refereed)
    Abstract [en]

    Optical directional couplers and Mach-Zehnder interferometers employing surface plasmon polaritons are proposed and their characteristics are analyzed numerically using a finite-difference time-domain method. It is shown that these devices can have transverse size smaller than the incident wavelength and can then be regarded as true subwavelength photonic elements. The ultra-compact characteristic of these devices can be utilized as a basis of next generation of integrated photonic circuits. Furthermore, calculations also show that these devices behave differently from their traditional all-dielectric counterparts. For the proposed optical directional coupler, the phase difference between the two output ports will no longer be 90 degrees even when the two ports have the same power outputs.

  • 37. Lu, Xiang
    et al.
    Cai, Yangjian
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    Analytical formulas for a circular or non-circular flat-topped beam propagating through an apertured paraxial optical system2007In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 269, no 1, p. 39-46Article in journal (Refereed)
    Abstract [en]

    Propagation of a flat-topped beam of circular or non-circular (rectangular or elliptical) symmetry through an apertured optical system is investigated. By expanding the hard aperture function as a finite sum of complex Gaussian functions, some approximate analytical propagation formulas are derived for a flat-topped beam of circular or non-circular (rectangular or elliptical) symmetry propagating through an apertured paraxial general astigmatic (GA) optical system or an apertured paraxial misaligned stigmatic (ST) optical system. The derived formulas are very fast to compute. The results obtained by using the approximate analytical expressions are in a good agreement with those obtained by direct numerical integration. The present analytical formulas provide a convenient and effective way for studying the propagation and transformation of a circular or non-circular flat-topped beam through an apertured general optical system.

  • 38.
    Lu, Yang
    et al.
    KTH. Hangzhou Dianzi University, China.
    Bi, M.
    Hu, M.
    Wei, Y.
    Yang, G.
    Zhou, X.
    Li, Q.
    Orthogonal modulation application to achieve flexible migration and colorless ONUs for next generation PON2017In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 403, p. 252-256Article in journal (Refereed)
    Abstract [en]

    Flexible migration that reuse the deployed infrastructure and colorless ONUs which avoid inventory problem are two major challenges of next-generation passive optical network (NGPON). In this paper, flexible migration is achieved by the coexistence of legacy PON and NGPON and colorless ONUs is achieved by upstream remodulation. Orthogonal modulation methods such as DPSK, PolSK and WSK are applied for NGPON downstream signal to ensure the constant amplitude. The amplitude-constant NGPON downstream signal induces low crosstalk to the coexisting legacy PON signal and the remodulated upstream signal. The experimental demonstration shows error free transmission and verifies the feasibility of the proposed scheme.

  • 39. Metwally, N
    et al.
    Wahiddin, M R B
    Bourennane, Mohamed
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Coherent information losses between two-qubit pair interacting with an environment2006In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 257, no 1, p. 206-215Article in journal (Refereed)
    Abstract [en]

    We quantify the amount of information exchanged between a system of two qubit pair and the environment. We find that there is a good chance for an Eavesdropper to distill information from the entangled qubits. This chance decreases for less entangled qubits. In particular, we considered two examples: The first is an entangled pure two qubit state and the second an entangled state from two cavities, with a depolarizing channel as an environment. Also the effect of decoherence due to the channel parameter is studied.

  • 40. Montes, Carlos
    et al.
    Picozzi, Antonio
    Gallo, Katia
    Optoelectronics Research Centre, University of Southampton.
    Ultra-coherent signal output from an incoherent cw-pumped singly resonant optical parametric oscillator2004In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 237, no 4-6, p. 437-449Article in journal (Refereed)
    Abstract [en]

    Incoherent broad-bandwidth cw-pumped singly resonant optical parametric oscillator (OPO), in the quasi-phase-matched non-degenerate configuration, may efficiently generate ultra-coherent signal output by the convection-induced phase-locking mechanism in which the incoherence of the pump is absorbed by the idler wave allowing the signal to become highly coherent. In actual nonlinear quadratic waveguide configurations one obtains signal spectral widths smaller than 5 x 10(-4) times the pump spectral width, and a reduction of the average signal intensity fluctuations by less than a factor 10(-4).

  • 41. Norman, P.
    et al.
    Luo, Y.
    Ågren, H.
    Two-photon absorption in five-membered heteroaromatic oligomers1999In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 168, no 1, p. 297-303Article in journal (Refereed)
    Abstract [en]

    Structure-to-property relations for the two-photon absorption intensities of oligothiophenes, oligopyrroles, and oligofurans have been studied using ab initio response theory. Power law dependences of the two-photon absorption intensities with respect to the length of the oligomers have been revealed, and localization lengths at which the intensities are completely dominated by one single state are found.

  • 42. Ostlund, P.
    et al.
    Friberg, Ari T.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Radiometry and far-zone polarization for partially coherent electromagnetic planar sources2001In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 197, no 03-jan, p. 1-8Article in journal (Refereed)
    Abstract [en]

    Making use of the rigorous vectorial far-field theory the generalized radiance of a stationary electromagnetic planar source is derived and expressions for the radiant intensity and the radiant emittance are introduced in terms of the spatial coherence properties of the source. A method for calculating the degree of polarization of the field in the far zone of an electromagnetic planar source is put forward and two examples demonstrating the technique are worked out.

  • 43. Ou, Haiyan
    et al.
    Fu, Hongyan
    Chen, Daru
    He, Sailing
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    A tunable and reconfigurable microwave photonic filter based on a Raman fiber laser2007In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 278, no 1, p. 48-51Article in journal (Refereed)
  • 44. Paakkonen, P.
    et al.
    Turunen, J.
    Vahimaa, P.
    Friberg, Ari T.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Wyrowski, F.
    Partially coherent Gaussian pulses2002In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 204, no 06-jan, p. 53-58Article in journal (Refereed)
    Abstract [en]

    The concept of a plane-wave pulse with a Gaussian spectrum and a Gaussian distribution of correlations between different frequency components is introduced. The temporal coherence properties of such a pulse are related to the spectral coherence properties and equivalence relations between pulses with different spectral and temporal correlation parameters are established.

  • 45.
    Petermann, Ingemar
    et al.
    Acreo AB, Electrum, Kista.
    Helmfrid, Sten
    Proximion AB, Kista.
    Friberg, Ari
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Limitations of the interferometric side diffraction technique for fibre Bragg grating characterization2002In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 201, no 4-6, p. 301-308Article in journal (Refereed)
    Abstract [en]

    We make a quantitative investigation of the interferometric side diffraction technique for characterization of fibre Bragg gratings. As opposed to more commonly used non-interferometric alternatives, this method also allows for determination of the grating's distributed phase. It is shown that for weak gratings the detected power and phase are directly proportional to the amplitude and phase of the refractive index modulation in the fibre. While the phase measurement is only limited by the amount of noise present, the relation between modulation amplitude and detected power becomes non-linear when using small probe beam wavelengths and gratings with a modulation depth Deltan approximate to 10(-3) and above. This behavior is inherent to the side diffraction and thus care has to be taken when performing apodization measurements on very strong gratings. The sensitivity to noise is briefly discussed and using a crude estimate for the noise level. the theory indicates that this method is suitable down to a grating modulation depth of at least Deltan approximate to 10(-5).

  • 46. Qiang, Z. X.
    et al.
    Wu, X.
    He, Sailing
    Lu, Z. K.
    The global analysis for an all-optical gain-clamped L-band erbium-doped fiber amplifier using a single fiber Bragg grating2003In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 224, no 01-3, p. 73-80Article in journal (Refereed)
  • 47.
    Rosa, A. N. F.
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab). Federal University of Para, Brazil.
    Wiatr, Pawel
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Cavdar, Cicek
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Carvalho, S. V.
    Costa, J. C. W. A.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Statistical analysis of blocking probability and fragmentation based on Markov modeling of elastic spectrum allocation on fiber link2015In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 354, p. 362-373Article in journal (Refereed)
    Abstract [en]

    In Elastic Optical Network (EON), spectrum fragmentation refers to the existence of non-aligned, small-sized blocks of free subcarrier slots in the optical spectrum. Several metrics have been proposed in order to quantify a level of spectrum fragmentation. Approximation methods might be used for estimating average blocking probability and some fragmentation measures, but are so far unable to accurately evaluate the influence of different sizes of:connection requests and do not allow in-depth investigation of blocking events and their relation to fragmentation. The analytical study of the effect of fragmentation on requests' blocking probability is still under explored In this work, we introduce new definitions for blocking that differentiate between the reasons for the blocking events. We developed a framework based on Markov modeling to calculate steady-state probabilities for the different blocking events and to analyze fragmentation related problems in elastic optical links under dynamic traffic conditions. This framework can also be used for evaluation of different definitions of fragmentation in terms of their relation to the blocking probability. We investigate how different allocation request sizes contribute to fragmentation and blocking probability. Moreover, we show to which extend blocking events, due to insufficient amount of available resources, become inevitable and, compared to the amount of blocking events due to fragmented spectrum, we draw conclusions on the possible gains one cart achieve by system defragmentation. We also show how efficient spectrum allocation policies really are in reducing the part of fragmentation that in particular leads to actual blocking events. Simulation experiments are carried out showing good match with our analytical results for blocking probability in a small scale scenario. Simulated blocking probabilities for the different blocking events are provided for a larger scale elastic optical link.

  • 48.
    Salo, Janne
    et al.
    KTH, School of Engineering Sciences (SCI), Physics.
    Barnett, S. M.
    Stenholm, Stig
    KTH, School of Engineering Sciences (SCI), Physics.
    Non-Markovian thermalisation of a two-level atom2006In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 259, no 2, p. 772-780Article in journal (Refereed)
    Abstract [en]

    We consider thermalisation and spontaneous decay of a two-level atom beyond the Markovian approximation. While the standard elimination of the continuum of radiation modes results in exponential decay represented by a Lindblad equation of motion, we use a simple toy model that takes into account the finite relaxation rate of the environment and present an exact non-Markovian master equation of the Nakajima-Zwanzig form. Because the exact derivation of non-Markovian equations has proved very difficult for all more realistic (and hence much more complicated) models, we analyze the master equation obtained and also discuss difficulties that are likely to arise with non-Markovian evolution operators.

  • 49. Sergeyev, S.
    et al.
    Popov, Sergei
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics.
    Friberg, Ari T.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Optics.
    Modeling polarization-dependent gain in fiber Raman amplifiers with randomly varying birefringence2006In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 262, no 1, p. 114-119Article in journal (Refereed)
    Abstract [en]

    We report a new stochastic model for studying the polarization-dependent gain in Raman fiber amplifiers with randomly varying birefringence as a function of the pump state of polarization and the polarization mode dispersion parameter. Our theoretical results agree with the previously obtained experimental data.

  • 50. Setala, T.
    et al.
    Tervo, J.
    Friberg, Ari T.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Theorems on complete electromagnetic coherence in the space-time domain2004In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 238, no 06-apr, p. 229-236Article in journal (Refereed)
    Abstract [en]

    Making use of a recently introduced degree of coherence of random electromagnetic fields, we show that some well-known results on second-order scalar coherence theory in the space-time domain hold within the electromagnetic context as well. In particular, we prove that for statistically stationary electromagnetic waves the following three properties are equivalent: (i) the field is completely coherent in the space-time domain, (ii) the field is monochromatic, and (iii) the electric mutual coherence tensor factors in the two spatial variables and is periodic in the time difference.

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