Enhanced continuous-wave four-wave mixing efficiency in nonlinear AlGaAs waveguides.

Enhancements of the continuous-wave four-wave mixing conversion efficiency and bandwidth are accomplished through the application of plasma-assisted photoresist reflow to reduce the sidewall roughness of sub-square-micron-modal area waveguides. Nonlinear AlGaAs optical waveguides with a propagation loss of 0.56 dB/cm demonstrate continuous-wave four-wave mixing conversion efficiency of -7.

Efficient continuous-wave four-wave mixing in bandgap-engineered AlGaAs waveguides.

We present a side-by-side comparison of the nonlinear behavior of four passive AlGaAs ridge waveguides where the bandgap energy of the core layers ranges from 1.60 to 1.79 eV.

Low propagation loss AlGaAs waveguides fabricated with plasma-assisted photoresist reflow.

We report low-loss deep-etch AlGaAs optical waveguides fabricated with nitrogen plasma-assisted photoresist reflow. The simultaneous application of a nitrogen plasma and heat is used to reduce the line edge roughness of patterned photoresist and limit the lateral spread of the photoresist patterns of submicron-scale waveguides. Comparison of the edge roughness of the etched sidewalls between the as-developed and smoothed photoresist etch samples show a reduction of the RMS roughness from 3.

All-optical amplitude-phase transmultiplexing of RZ-OOK and RZ-BPSK to RZ-QPSK by polarization-insensitive XPM using a nonlinear birefringent AlGaAs waveguide.

Polarization-insensitive (PI) phase-transmultiplexing (PTM) of a 10-Gb/s return-to-zero ON-OFF keying (RZ-OOK) pump and a 10-Gb/s RZbinary phase-shift keying (RZ-BPSK) probe to 20-Gb/s RZ-quadrature-PSK (RZ-QPSK) has been successfully demonstrated for the first time in a passive, birefringent AlGaAs waveguide, utilizing PI cross-phase modulation (PI-XPM). For differential QPSK (DQPSK)-detection, a 10 − 9-BER pre-amplified receiver sensitivity penalty of ≈ 2.5 dB for the in-phase component and ≈ 4.

Nonlinearities in porous silicon optical waveguides at 1550 nm.

We report an experimental investigation of the nonlinear optical properties of nanoporous silicon optical waveguides measured at 1550 nm. The nonlinear properties including two-photon absorption, self-phase modulation, free-carrier absorption and free-carrier plasma dispersion are characterized and compared with similar measurements conducted on a conventional silicon-on-insulator ridge waveguide. Our study reveals that even waveguides that are 70% porous exhibit two-photon absorption and self-phase modulation coefficients that are comparable to those of crystalline silicon.