The Experts below are selected from a list of 79953 Experts worldwide ranked by ideXlab platform
Tian-bo Deng - One of the best experts on this subject based on the ideXlab platform.
-
ISCAS (1) - Complex-Coefficient variable filter design using successive vector-array-decomposition
2005 IEEE International Symposium on Circuits and Systems, 2005Co-Authors: Tian-bo DengAbstract:Singular-value-decomposition (SVD) can be efficiently utilized to obtain the optimal vector-array-decomposition (VAD) for simplifying real-Coefficient variable digital filter design problem, but the SVD-based VAD methods cannot be utilized to design Complex-Coefficient variable filters. The paper proposes a successive algorithm for decomposing an arbitrary multi-dimensional Complex array into the VAD form, and thus a Complex-Coefficient digital filter with an arbitrary variable frequency response can be easily obtained through Complex-Coefficient constant filter design and multi-dimensional polynomial fitting. The new VAD algorithm successively decomposes the Complex array and its residual arrays into the vector-array pairs stage-by-stage, and each stage contains an iterative optimization that can be easily solved in a closed-form. Our computer simulations have verified that the successive VAD converges very fast to the optimal solution.
-
Design of Complex-Coefficient variable digital filters using successive vector-array decomposition
IEEE Transactions on Circuits and Systems I: Regular Papers, 2005Co-Authors: Tian-bo DengAbstract:Singular-value decomposition (SVD) can be efficiently utilized to obtain the optimal vector-array decomposition (VAD) for simplifying real-Coefficient variable digital filter design problem, but the SVD-based VAD methods are not applicable to the design of Complex-Coefficient variable filters. This paper proposes a successive algorithm for decomposing arbitrary multidimensional Complex array into the VAD form, and thus, a Complex-Coefficient variable digital filter with arbitrary variable frequency response can be easily obtained through constant Complex-Coefficient filter design and multidimensional polynomial fitting. The new VAD algorithm successively decomposes the Complex array and its residual arrays into the vector-array pairs stage by stage, and each stage contains an iterative optimization that can be easily solved in a closed-form. Our computer simulations have demonstrated that the successive VAD converges very fast to the optimal solution.
Alan E Willner - One of the best experts on this subject based on the ideXlab platform.
-
experimental characterization of phase tuning using fine wavelength offsets in a tunable Complex Coefficient optical tapped delay line
Optics Letters, 2014Co-Authors: Salman Khaleghi, Mohammad Reza Chitgarha, Omer F Yilmaz, Moshe Tur, Michael W Haney, Carsten Langrock, M M Fejer, Alan E WillnerAbstract:We use fine-detuning of pump wavelengths to adjust the tap phases in a Complex-Coefficient optical tapped-delay-line that utilizes conversion/dispersion-based delays and nonlinear wave mixing. Full 2π phase tuning is demonstrated by detuning the frequency of laser pumps by <20 GHz, which shows close agreement with theory.
-
reconfigurable optical quadrature amplitude modulation converter encoder using a tunable Complex Coefficient optical tapped delay line
Optics Letters, 2013Co-Authors: Salman Khaleghi, Mohammad Reza Chitgarha, Omer F Yilmaz, Moshe Tur, Michael W Haney, Carsten Langrock, M M Fejer, Alan E WillnerAbstract:We experimentally demonstrate a reconfigurable optical converter/encoder for quadrature amplitude modulated (QAM) signals. The system utilizes nonlinear wavelength multicasting, conversion-dispersion delays, and simultaneous nonlinear multiplexing and sampling. We show baud rate tunability (31 and 20 Gbaud) and reconfigurable conversions from lower-order QAM signals to higher-order QAM signals (e.g., 64-QAM).
-
experimental performance of a fully tunable Complex Coefficient optical fir filter using wavelength conversion and chromatic dispersion
Optics Letters, 2012Co-Authors: Salman Khaleghi, Mohammad Reza Chitgarha, Omer F Yilmaz, Michael W Haney, Carsten Langrock, M M Fejer, Alan E WillnerAbstract:We experimentally characterize the performance of a continuously tunable all-optical Complex-Coefficient finite-impulse-response (FIR) filter that exploits nonlinear signal processing (multiplexing and multicasting) and conversion-dispersion-based optical delays. Various length (three and four) optical FIR filters with different tap amplitudes (from 0 to −9 dB), tap phases (from 0 to 2π), and tap delays (∼37.4 ps and 25 ps) are realized, showing reconfiguration and tuning capabilities of this FIR filter. The measured frequency responses show close agreement with the theoretical filter responses.
-
experimental characterization of phase tuning using fine wavelength offset in a Complex Coefficient optical fir filter
Conference on Lasers and Electro-Optics, 2012Co-Authors: Salman Khaleghi, Mohammad Reza Chitgarha, Omer F Yilmaz, Moshe Tur, Michael W Haney, Carsten Langrock, M M Fejer, Alan E WillnerAbstract:We propose and characterize varying the tap-phases of the recently introduced Complex-Coefficient tunable conversion/dispersion based FIR filter by fine tuning of pump lasers. Full tap-phase tuning (− π to π) is achieved by detuning the frequency of laser pumps by <10GHz, with close agreement to the theory.
-
universal qam encoder converter using fully tunable Complex Coefficient optical tapped delay line
Optical Fiber Communication Conference, 2012Co-Authors: Salman Khaleghi, Mohammad Reza Chitgarha, Omer F Yilmaz, Moshe Tur, Michael W Haney, Alan E WillnerAbstract:We experimentally demonstrate a tunable and reconfigurable optical scheme for encoding and converting of QAM symbols. 20/31 Gbaud QPSK signals are encoded/converted to higher order QAMs, including 64-QAM in an all-optical tunable tapped delay line. The OSNR penalty at 2×10−3 BER is measured to be ∼2 dB and ∼8 dB for conversions of 31 Gbaud BPSK to 15.5 Gbaud QPSK and 31 Gbaud QPSK to 15.5 Gbaud 16-QAM, respectively.
Jianping Yao - One of the best experts on this subject based on the ideXlab platform.
-
a continuously tunable multi tap Complex Coefficient microwave photonic filter based on a tilted fiber bragg grating
Optics Express, 2013Co-Authors: Hiva Shahoei, Jianping YaoAbstract:The coupling Coefficients of the cladding-mode resonances of a tilted fiber Bragg grating (TFBG) are linearly increasing or decreasing in different wavelength regions. Based on the Kramers-Kronig relations, when the coupling Coefficients are linearly increasing, the phase shifts are linearly increasing correspondingly. This feature is employed, for the first time, for the implementation of a multi-tap continuously tunable microwave photonic filter with Complex Coefficients by using a TFBG. By locating the optical carriers of single-sideband-modulated signals at the cladding-mode resonances of the TFBG which has linearly increasing depths, linearly increasing phase shifts are introduced to the optical carriers. By beating the optical carriers with the single sidebands, the phase shifts are translated to the microwave signals, and thus Complex Coefficients with the required linearly increasing phase shifts are generated. The tunability of the Complex Coefficients is realized by optically pumping the TFBG which is written in an erbium/ytterbium (Er/Yb) co-doped fiber. A proof-of-concept experiment is performed; a three- and four-tap filter with a frequency tunable range of 150 and 120 MHz, respectively, are demonstrated.
-
a tunable photonic microwave filter with a Complex Coefficient using an optical rf phase shifter
IEEE Photonics Technology Letters, 2007Co-Authors: Yu Yan, Jianping YaoAbstract:A novel tunable photonic microwave filter with Complex Coefficients is proposed and experimentally demonstrated. The Complex Coefficient is generated using a wideband tunable optical RF phase shifter that consists of two electrooptic intensity modulators. The phase of the RF signal is shifted by simply adjusting the bias voltages applied to the two electrooptic intensity modulators, and the phase shift remains constant over the microwave spectral region of interest. A two-tap photonic microwave filter with one tunable Complex Coefficient, with a wide and continuous tuning range, is experimentally demonstrated.
Salman Khaleghi - One of the best experts on this subject based on the ideXlab platform.
-
experimental characterization of phase tuning using fine wavelength offsets in a tunable Complex Coefficient optical tapped delay line
Optics Letters, 2014Co-Authors: Salman Khaleghi, Mohammad Reza Chitgarha, Omer F Yilmaz, Moshe Tur, Michael W Haney, Carsten Langrock, M M Fejer, Alan E WillnerAbstract:We use fine-detuning of pump wavelengths to adjust the tap phases in a Complex-Coefficient optical tapped-delay-line that utilizes conversion/dispersion-based delays and nonlinear wave mixing. Full 2π phase tuning is demonstrated by detuning the frequency of laser pumps by <20 GHz, which shows close agreement with theory.
-
reconfigurable optical quadrature amplitude modulation converter encoder using a tunable Complex Coefficient optical tapped delay line
Optics Letters, 2013Co-Authors: Salman Khaleghi, Mohammad Reza Chitgarha, Omer F Yilmaz, Moshe Tur, Michael W Haney, Carsten Langrock, M M Fejer, Alan E WillnerAbstract:We experimentally demonstrate a reconfigurable optical converter/encoder for quadrature amplitude modulated (QAM) signals. The system utilizes nonlinear wavelength multicasting, conversion-dispersion delays, and simultaneous nonlinear multiplexing and sampling. We show baud rate tunability (31 and 20 Gbaud) and reconfigurable conversions from lower-order QAM signals to higher-order QAM signals (e.g., 64-QAM).
-
experimental performance of a fully tunable Complex Coefficient optical fir filter using wavelength conversion and chromatic dispersion
Optics Letters, 2012Co-Authors: Salman Khaleghi, Mohammad Reza Chitgarha, Omer F Yilmaz, Michael W Haney, Carsten Langrock, M M Fejer, Alan E WillnerAbstract:We experimentally characterize the performance of a continuously tunable all-optical Complex-Coefficient finite-impulse-response (FIR) filter that exploits nonlinear signal processing (multiplexing and multicasting) and conversion-dispersion-based optical delays. Various length (three and four) optical FIR filters with different tap amplitudes (from 0 to −9 dB), tap phases (from 0 to 2π), and tap delays (∼37.4 ps and 25 ps) are realized, showing reconfiguration and tuning capabilities of this FIR filter. The measured frequency responses show close agreement with the theoretical filter responses.
-
experimental characterization of phase tuning using fine wavelength offset in a Complex Coefficient optical fir filter
Conference on Lasers and Electro-Optics, 2012Co-Authors: Salman Khaleghi, Mohammad Reza Chitgarha, Omer F Yilmaz, Moshe Tur, Michael W Haney, Carsten Langrock, M M Fejer, Alan E WillnerAbstract:We propose and characterize varying the tap-phases of the recently introduced Complex-Coefficient tunable conversion/dispersion based FIR filter by fine tuning of pump lasers. Full tap-phase tuning (− π to π) is achieved by detuning the frequency of laser pumps by <10GHz, with close agreement to the theory.
-
universal qam encoder converter using fully tunable Complex Coefficient optical tapped delay line
Optical Fiber Communication Conference, 2012Co-Authors: Salman Khaleghi, Mohammad Reza Chitgarha, Omer F Yilmaz, Moshe Tur, Michael W Haney, Alan E WillnerAbstract:We experimentally demonstrate a tunable and reconfigurable optical scheme for encoding and converting of QAM symbols. 20/31 Gbaud QPSK signals are encoded/converted to higher order QAMs, including 64-QAM in an all-optical tunable tapped delay line. The OSNR penalty at 2×10−3 BER is measured to be ∼2 dB and ∼8 dB for conversions of 31 Gbaud BPSK to 15.5 Gbaud QPSK and 31 Gbaud QPSK to 15.5 Gbaud 16-QAM, respectively.
J Capmany - One of the best experts on this subject based on the ideXlab platform.
-
multi tap Complex Coefficient incoherent microwave photonic filters based on optical single sideband modulation and narrow band optical filtering
Optics Express, 2008Co-Authors: Mikel Sagues, Raimundo Garcia Olcina, Alayn Loayssa, Salvador Sales, J CapmanyAbstract:We propose a novel scheme to implement tunable multi-tap Complex Coefficient filters based on optical single sideband modulation and narrow band optical filtering. A four tap filter is experimentally demonstrated to highlight the enhanced tuning performance provided by Complex Coefficients. Optical processing is performed by the use of a cascade of four phase-shifted fiber Bragg gratings specifically fabricated for this purpose.
-
Multitap Complex-Coefficient Incoherent Microwave Photonic Filters Based on Stimulated Brillouin Scattering
IEEE Photonics Technology Letters, 2007Co-Authors: Mikel Sagues, Alayn Loayssa, J CapmanyAbstract:We propose a novel scheme to implement multitap tunable incoherent microwave photonic filters with all-optical Complex Coefficients based on Brillouin signal processing of optical single-sideband signals. A six-tap filter is experimentally demonstrated to highlight the enhanced flexibility in the synthesis of frequency responses provided by Complex Coefficients, particularly in terms of tuning.
-
Multitap Complex-Coefficient Incoherent Microwave Photonic Filters Based on Stimulated
2007Co-Authors: Mikel Sagues, Alayn Loayssa, J CapmanyAbstract:We propose a novel scheme to implement multitap tunable incoherent microwave photonic filters with all-optical Complex Coefficients based on Brillouin signal processing of optical single-sideband signals. A six-tap filter is experimentally demon- strated to highlight the enhanced flexibility in the synthesis of frequency responses provided by Complex Coefficients, particularly in terms of tuning.
-
Demonstration of incoherent microwave photonic filters with all-optical Complex Coefficients
IEEE Photonics Technology Letters, 2006Co-Authors: Alayn Loayssa, Mikel Sagues, J Capmany, Jose MoraAbstract:We propose and demonstrate for the first time to our knowledge an incoherent microwave photonic filter with Complex Coefficients implemented in the optical domain. The system is based on a tunable optically induced RF phase-shift that is obtained by means of a novel optical signal processing technique that makes combined use of optical single-sideband modulation and stimulated Brillouin scattering. A two-tap filter is built demonstrating full tunability of its frequency response by dynamically changing the phase shift of a Complex Coefficient