The Experts below are selected from a list of 8199 Experts worldwide ranked by ideXlab platform
Alan E Willner - One of the best experts on this subject based on the ideXlab platform.
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psa design counting longitudinal Chromatic Dispersion fluctuation in highly nonlinear fiber
Opto-Electronics and Communications Conference, 2018Co-Authors: Youichi Akasaka, Alan E Willner, Haoqian Song, Fatemeh Alishahi, Tadashi IkeuchiAbstract:A potential tool to make HNLF based phase-sensitive-amplifier optimize is proposed. Experimental data is implemented to incorporate longitudinal Chromatic Dispersion fluctuation of highly-nonlinear-fiber. PSA gain and noise characteristics can be estimated well with it.
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free spectral range optimization of return to zero differential phase shift keyed demodulation in the presence of Chromatic Dispersion
Optics Express, 2007Co-Authors: Y K Lize, Alan E Willner, L Christen, Jengyuan Yang, Scott R Nuccio, Raman KashyapAbstract:Optical differential phase shift keying is normally demodulated in a delay-line interferometer with a 1-bit delay such that the free-spectral-range of the demodulator is equal to the transmitted bitrate. We show using Karkunen-Loeve expansion simulation that free-spectral-range optimization leads to increased Chromatic Dispersion tolerances. The optimized delay inversely scales with the amount of Chromatic Dispersion such that a delay slightly shorter than the bit period increases tolerances with no adverse effect on the polarization-mode-Dispersion tolerance or frequency offset penalty at the receiver.
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Chromatic Dispersion insensitive dgd monitoring by adding a frequency shifted carrier along the orthogonal polarization state
Lasers and Electro-Optics Society Meeting, 2003Co-Authors: T Luo, Zhongqi Pan, Y Wang, A Yoel, Alan E WillnerAbstract:We demonstrate accurate DGD monitoring by adding a frequency-shifted carrier along the orthogonal polarization state and extracting the regenerated RF power near the bit-rate frequency. This monitoring signal is insensitive to Chromatic Dispersion.
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Chromatic Dispersion monitoring technique using sideband optical filtering and clock phase shift detection
Journal of Lightwave Technology, 2002Co-Authors: Zhongqi Pan, Lianshan Yan, Alan E WillnerAbstract:We propose and demonstrate a novel technique for 40- and 10-Gb/s Chromatic Dispersion monitoring that uses an optical filter to select the upper and lower vestigial-sideband (VSB) signals in the transmitted optical data and determine the relative clock phase shift caused by Dispersion. Without modification of transmitters, this technique provides low cost Chromatic Dispersion monitoring for WDM systems, <3 ps/nm Dispersion resolution for 40-Gb/s data, and greatly reduced sensitivity to the influence of polarization mode Dispersion.
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fixed and tunable management of fiber Chromatic Dispersion
Optical Fiber Telecommunications IV-B (Fourth Edition), 2002Co-Authors: Alan E Willner, Bogdan HoancaAbstract:Publisher Summary It is noted that the essence of Chromatic Dispersion lies in the fact that in any medium other than a vacuum and in any waveguide structure, different electromagnetic frequencies propagate at different speeds. Chromatic Dispersion in optical fibers is therefore, because of the frequency–dependent nature of the propagation characteristics, for both the material and the waveguide structure. Chromatic Dispersion, essentially, is a linear effect that can be compensated by adding the complementary Dispersion before any significant nonlinearities intervene. It is noted that nonlinearities do intervene in many of the systems and the periodic Dispersion mapping is required for managing them. The issues surrounding the compensation of Chromatic Dispersion in high-performance optical systems have been addressed in the chapter. The chapter also describes the effects of Dispersion, the various fixed compensation techniques, the need for tunable compensation and its potential solutions, and also the techniques for monitoring accumulated Dispersion. Chromatic Dispersion phenomenon exhibits profound implications for opticalfiber communications systems.
A L Campillo - One of the best experts on this subject based on the ideXlab platform.
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Chromatic Dispersion monitoring technique based on phase sensitive detection
IEEE Photonics Technology Letters, 2005Co-Authors: A L CampilloAbstract:A novel Chromatic Dispersion-monitoring technique is proposed and demonstrated. A path imbalanced interferometer is used to monitor the intensity to phase conversion of a radio-frequency spectral component of a modulated signal. The measurement range of the technique is independent of the data rate and can be tuned by adjusting the path length difference of the interferometer. An unambiguous measurement range of >2300 ps/nm is demonstrated for a 10-GB/s nonreturn-to-zero signal.
Masanori Koshiba - One of the best experts on this subject based on the ideXlab platform.
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ultra flattened Chromatic Dispersion controllability using a defected core photonic crystal fiber with low confinement losses
Optics Express, 2005Co-Authors: Kunimasa Saitoh, N J Florous, Masanori KoshibaAbstract:The present paper describes a novel systematic solution to the problem of controlling the Chromatic Dispersion and Dispersion slope in photonic crystal fibers (PCFs), using a structurally-simple PCF with a defected-core. By adjusting the size of the central air-hole defect we can successfully design an ultra-flattened PCF with low confinement losses, as well as small effective mode area. The design strategy is based on the mutual cancellation between the waveguide and the material Dispersions of the PCF, by varying the size of the central defected region in the core. The verification of the ultra-flattened Chromatic Dispersion property of the proposed PCF is ensured with an accurate full-vector finite element method with anisotropic perfectly matched layers. The ultra-flattened Dispersion feature, as well as the low confinement losses and the small effective mode area are the main advantages of the proposed PCF structure, making it suitable as a Chromatic Dispersion controller, Dispersion compensator, or as candidate for nonlinear optical applications.
M Ohashi - One of the best experts on this subject based on the ideXlab platform.
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Chromatic Dispersion diagnosis for the two modes of few mode photonic crystal fiber
IEEE Photonics Technology Letters, 2016Co-Authors: Nori Shibata, Kimitaka Watanabe, M OhashiAbstract:We provide the differential group delay (DGD) and Chromatic Dispersion for the fundamental and first higher order modes traversing a large-core few-mode photonic crystal fiber (PCF). The modal interferometer method is used to measure the DGD and Chromatic Dispersion for the fundamental mode at a wavelength of $\sim 1300$ nm and in the 1450–1625-nm telecommunication band. The combined measurement of the DGD and Chromatic Dispersion makes it possible to obtain the Chromatic Dispersion of the higher order mode. The Chromatic Dispersion diagnosis for the two modes is discussed. In the 1450–1625-nm band, the results obtained experimentally for the two modes exactly match those obtained from the empirical relations for PCF Dispersion.
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measurements of differential group delay and Chromatic Dispersion for lp01 and lp11 modes of few mode fibers with depressed claddings
Optical Review, 2015Co-Authors: Nori Shibata, M Ohashi, Ryo Maruyama, Nobuo KuwakiAbstract:The Chromatic Dispersion of the LP11 mode in a few-mode fiber with low differential group delay is evaluated experimentally. A differential group delay of less than 100 ps/km around 1550 nm can be evaluated with the modal interferometer method. The white-light interferometric method confirms that the LP11 mode is behind the LP01 mode in the 1300–1600 nm wavelength region. The difference between the Chromatic Dispersion values of the two modes is less than 0.5 ps/km/nm, which means that the optical pulse spreading characteristics of the LP11 mode are similar to those of the LP01 mode for fibers with depressed claddings.
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Chromatic Dispersion distribution measurement along a single mode optical fiber
Journal of Lightwave Technology, 1997Co-Authors: Kazuhide Nakajima, M Ohashi, Mitsuhiro TatedaAbstract:A nondestructive measurement technique, which uses a four-wavelength bidirectional optical time domain reflectometer (OTDR) to measure the Chromatic Dispersion distribution along a single-mode fiber, is compared with the destructive interferometric technique. The experimental results obtained by this technique are in good agreement with those obtained by the interferometric technique. In addition, a measurement procedure is proposed for a transmission line composed of different types of single-mode fiber. These results show that this technique is extremely useful for the design of wavelength division multiplexer (WDM) and finite difference multiplexer (FDM) optical communication systems.
Biao Fu - One of the best experts on this subject based on the ideXlab platform.
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fiber Chromatic Dispersion and polarization mode Dispersion monitoring using coherent detection
IEEE Photonics Technology Letters, 2005Co-Authors: Biao FuAbstract:We propose and experimentally demonstrate a nondestructive method to monitor Chromatic Dispersion (CD) and polarization-mode Dispersion (PMD) in traffic-carrying wavelength-division-multiplexing optical systems. Coherent heterodyne detection is used to down convert the spectrum of digitally modulated signal from optical domain into radio-frequency (RF) domain. By analyzing group delay difference and polarization walkoff between different frequency components through proper RF signal processing, both CD and PMD can be precisely determined. Good agreement between experimental results and theoretical values has been obtained.