Omer F. Yilmaz
University of Southern California
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Publication
Featured researches published by Omer F. Yilmaz.
Journal of Lightwave Technology | 2014
Alan E. Willner; Salman Khaleghi; Mohammad Reza Chitgarha; Omer F. Yilmaz
Optical signal processing brings together various fields of optics and signal processing - namely, nonlinear devices and processes, analog and digital signals, and advanced data modulation formats - to achieve high-speed signal processing functions that can potentially operate at the line rate of fiber optic communications. Information can be encoded in amplitude, phase, wavelength, polarization and spatial features of an optical wave to achieve high-capacity transmission. We revisit advances in the key enabling technologies that led to recent research in optical signal processing for digital signals that are encoded in one or more of these dimensions. Various optical nonlinearities and chromatic dispersion have been shown to enable key sub-system applications such as wavelength conversion, multicasting, multiplexing, demultiplexing, and tunable optical delays. We review recent advances in high-speed optical signal processing applications in the areas of equalization, regeneration, flexible signal generation, and optical control information (optical logic and correlation).
IEEE Journal of Selected Topics in Quantum Electronics | 2011
Alan E. Willner; Omer F. Yilmaz; Jian Wang; Xiaoxia Wu; Antonella Bogoni; Lin Zhang; Scott R. Nuccio
Optical signal processing techniques employ a wide range of devices and various nonlinearities to achieve multiple network functionalities. The choice of nonlinearity can also impact the relative efficiency, both in terms of energy and material consumption, of the signal processing function being implemented. Techniques for some of the important functionalities, wavelength multicasting, wavelength-division multiplexing to time-division multiplexing, add-drop multiplexing, and wavelength exchange are compared in terms of the used optical spectrum, number of pumps required, and optical energy consumed. These include varieties of four-wave mixing, cross-phase modulation, Kerr-effect-based polarization rotation in optical fibers, and three-wave mixing in lithium niobate waveguides (WGs). Future possibilities of greener optical signal processing using on-chip WG technologies are discussed within the scope of recent developments in the dispersion tailored, highly nonlinear WGs.
Optics Express | 2011
Asher Voskoboinik; Omer F. Yilmaz; Alan Willner; Moshe Tur
A frequency-sweep-free method for distributed Brillouin sensing is proposed, having the potential for fast dynamic strain measurements. In this reported implementation of the method, multiple probe waves with carefully chosen optical frequencies simultaneously propagate in the fiber against an equal number of sequentially-launched, short pump pulses of matching frequencies, where each of pump-probe pair replaces one sweeping step in the classical BOTDA technique. Experimentally, distributed sensing is demonstrated with a spatial resolution of a few meters.
IEEE Photonics Technology Letters | 2008
Jeng-Yuan Yang; Lin Zhang; Xiaoxia Wu; Omer F. Yilmaz; Bo Zhang; Alan E. Willner
We propose and experimentally demonstrate an all-optical chromatic dispersion (CD) monitoring technique for phase-modulated signals utilizing the cross-phase-modulation effect between the input signal and the inserted continuous-wave probe. The probes optical spectrum changes with the accumulated CD on the input signal, indicating that the optical power variations can be measured for monitoring. The experimental results show that this technique can monitor up to 120 ps/nm of CD for a 40-Gb/s return-to-zero differential phase-shift keying (RZ-DPSK) transmission system, with the maximum measured optical power increment of 16.5 dB. The applicability of this monitoring technique to higher bit-rate phase-modulated signals, such as 80-Gb/s RZ differential quadrature phase-shift keying and 80-Gb/s polarization-multiplexed RZ-DPSK, is also investigated via simulation.
Optics Letters | 2009
Louis Christen; Omer F. Yilmaz; Scott R. Nuccio; Xiaoxia Wu; Irfan Fazal; Alan E. Willner; Carsten Langrock; Martin M. Fejer
We demonstrate a variable, optical-delay element using tunable wavelength conversion in a periodically poled lithium niobate waveguide, dispersion-compensating fiber and intrachannel dispersion compensation. A delay of up to 105 ns is demonstrated using 80 Gb/s return-to-zero differential-quadrature phase-shift keying, 40 Gb/s return-to-zero differential phase-shift keying, and 40 Gb/s return-to-zero on-off keying modulation formats. Bit-error rates <10−9 are demonstrated for each waveform at various delay settings.
IEEE Photonics Journal | 2012
Salman Khaleghi; Omer F. Yilmaz; Mohammad Reza Chitgarha; Moshe Tur; Nisar Ahmed; Scott R. Nuccio; Irfan Fazal; Xiaoxia Wu; Michael W. Haney; Carsten Langrock; Martin M. Fejer; Alan E. Willner
We demonstrate a reconfigurable high-speed optical tapped delay line (TDL), enabling several fundamental real-time signal processing functions such as correlation (for pattern search) and equalization. Weighted taps are created and added using optical multicasting and multiplexing schemes that utilize the nonlinear wave mixings in the periodically poled lithium niobate (PPLN) waveguides. Tunable tap delays are realized using the conversion-dispersion technique. In the demonstrated TDL, the amplitude and phase of tap coefficients can be varied, enabling signal processing on amplitude- and phase-encoded optical signals. We experimentally demonstrate the tunability of the TDL in time, amplitude, and phase. We analyze the TDLs theory of operation and present experimental results on reconfigurable pattern search (correlation) on on-off-keyed and phase-shift-keyed signals at data rates of up to 80 Gb/s, as well as equalization for chromatic dispersion.
optical fiber communication conference | 2011
Scott R. Nuccio; Zahra Bakhtiari; Omer F. Yilmaz; Alan E. Willner
We experimentally demonstrate wavelength conversion of both single polarization 40-Gbuad 16-QAM and 20-Gbuad polarization-division-multiplexed (PDM) 16-QAM in a PPLN waveguide. A polarization insensitive scheme utilizing bi-directional operation is employed. The power penalty as a function of pump power is also investigated and a minimum conversion penalty of ∼0.5 dB is obtained.
Optics Letters | 2010
Jian Wang; Zahra Bakhtiari; Scott R. Nuccio; Omer F. Yilmaz; Xiaoxia Wu; Alan E. Willner
We report the phase-transparent optical data exchange of differential phase-shift keying (DPSK) signals by exploiting the parametric depletion of nondegenerate four-wave mixing (FWM) in a highly nonlinear fiber. Theoretical analyses of nondegenerate FWM involving two signals and two pumps are presented. Analytical solutions are derived, indicating the exchange condition and the feasibility of phase-transparent data exchange. Optical data exchange between 10.7 Gbit/s non-return-to-zero DPSK (NRZ-DPSK) and return-to-zero DPSK signals is implemented with a power penalty of approximately 1.5 dB at a bit-error rate (BER) of 10(-9). Moreover, we demonstrate phase-transparent optical data exchange between two 40 Gbit/s NRZ-DPSK signals with a power penalty of approximately 4.5 dB at a BER of 10(-9).
IEEE Journal of Selected Topics in Quantum Electronics | 2010
Xiaoxia Wu; Antonella Bogoni; Scott R. Nuccio; Omer F. Yilmaz; Mirco Scaffardi; Alan E. Willner
We experimentally demonstrate several high-speed wavelength division multiplexing (WDM) to time division multiplexing (TDM) conversion schemes by using different nonlinearities in highly nonlinear fiber (HNLF). 40-160-Gb/s WDM-to-TDM conversion using cross-phase modulation (XPM) and 160-320-Gb/s conversion based on supercontinuum generation are shown. Furthermore, we investigate a different kind of HNLF, and demonstrate 40-80-Gb/s WDM-to-TDM conversion using XPM in a 0.8-m bismuth oxide HNLF (Bi-HNLF). Less than 3-dB power penalty is obtained for each case.
Optics Letters | 2012
Yang Yue; Hao Huang; Lin Zhang; Jian Wang; Jeng-Yuan Yang; Omer F. Yilmaz; Jacob S. Levy; Michal Lipson; Alan E. Willner
We propose and experimentally demonstrate UWB monocycle generation using non-degenerated two-photon absorption in a silicon waveguide. A 8.69-GHz 10-dB bandwidth (BW) and a 154.5% fractional bandwidth is achieved with a ∼125 ps monocycle pulse.