Anthony S. Lenihan

All-optical 80-gb/s time-division demultiplexing using polarization-insensitive cross-phase modulation in photonic crystal fiber

We describe an all-optical 80-Gb/s time-division demultiplexer, which utilizes cross-phase modulation in a commercial photonic crystal fiber. Compared to back-to-back 10-Gb/s measurements, the demultiplexer achieves better than a 2.5-dB power penalty for all eight channels. More importantly, we demonstrate a novel scheme for polarization-insensitive operation, which uses only the birefringence of the fiber itself and proper alignment of the clock pulse polarization. Using this technique, the polarization sensitivity of the converted power is found to be less than 0.4 dB, allowing for error-free demultiplexing even while the data polarization state is scrambled

Erratum to “Polarization-Insensitive Wavelength Conversion by FWM in a Highly Nonlinear PCF of Polarization-Scrambled 10-Gb/s RZ-OOK and RZ-DPSK Signals”

Wavelength conversion of polarization-scrambled 10-Gb/s on-off keyed and differential phase-shift-keyed signals for which the pulse format was 33% return-to-zero, has been achieved by partially degenerate four-wave mixing in a record 20-m-short highly nonlinear photonic crystal fiber. It was found that a minimum pump-probe detuning of ~9 nm was required to achieve polarization-insensitive wavelength conversion of <1 dB, resulting in a 10-9-receiver sensitivity penalty of <1 dB, for both modulation formats.

160-Gb/s Polarization-Independent Optical Demultiplexing in 2-m Nonlinear Fiber

We report a new method for polarization-independent optical demultiplexing that uses cross-phase modulation (XPM) in nonlinear fiber. Using this technique, we achieved error-free 160- to 10-Gb/s demultiplexing in only 2 m of highly nonlinear bismuth-oxide fiber. The demultiplexing performance is not impaired when the input data polarization state is scrambled at high speed. This method does not require circular polarization states and is shown to work even in birefringent fibers. We present a simple theoretical model that predicts the conditions under which polarization-independent XPM can be achieved, and we show numerical simulations that agree well with experimental observations

An experimental demonstration of a soft-failure approach to PMD mitigation in an installed optical link.

We present a field-trial implementation of the soft-failure approach to polarization-mode dispersion (PMD) impairment mitigation, in which information about the PMD of the installed link is utilized by our modified control plane software to make decisions on data routing over available links. This allows us to maintain loss-free end-to-end data service, even at high PMD levels.

Polarization-Insensitive Wavelength Conversion at 40 Gb/s Using Birefringent Nonlinear Fiber

Polarization-insensitive cross-phase modulation in a birefringent nonlinear photonic crystal fiber is used to realize wavelength conversion at 40 Gb/s. Error-free performance for polarization scrambled signals is obtained.

Techniques for Polarization-Independent Cross-Phase Modulation in Nonlinear Birefringent Fibers

We present a theoretical, numerical, and experimental investigation of the polarization dependence of cross-phase modulation in nonlinear birefringent fibers. Two new methods are described for producing a polarization-independent spectral shift through cross-phase modulation of a weak probe signal by a copropagating strong optical pulse. The birefringence of the fiber and spectral separation between the pump and probe signals are shown to play a critical role in determining the polarization dependence of the cross-phase modulation process. The methods are experimentally verified in two different highly nonlinear fibers, and are used to achieve polarization-independent optical switching at speeds of up to 160 Gb/s.

High-speed polarization independent demultiplexing using birefringent nonlinear fiber

We describe a technique for achieving polarization-independent nonlinear interactions in a short nonlinear fiber, through the residual birefringence of the fiber. We apply this method to all-optical demultiplexing of high data rate signals.

80 Gb/s polarization-independent optical demultiplexing in highly nonlinear Bismuth-oxide fiber

We report a polarization-independent 80 Gb/s optical demultiplexer based on cross-phase modulation in 2 meters of bismuth-oxide fiber. We show error- and penalty-free performance even when the polarization state is randomly scrambled.