Difference frequency generation by quasi-phase matching in periodically intermixed semiconductor superlattice waveguides

Wavelength conversion by difference frequency generation is demonstrated in domain-disordered quasi-phase-matched waveguides. The waveguide structure consisted of a GaAs/AlGaAs superlattice core that was periodically intermixed by ion implantation. For quasi-phase-matching periods of 3.0–3.8 μm, degeneracy pump wavelengths were found by second-harmonic generation experiments for fundamental wavelengths between 1520 and 1620 nm in both type-I and type-II configurations. In the difference frequency generation experiments, output powers up to 8.7 nW were generated for the type-I phase matching interaction and 1.9 nW for the type-II interaction. The conversion bandwidth was measured to be over 100 nm covering the C, L, and U optical communications bands, which agrees with predictions

Quantum well and dot self-aligned stripe lasers utilizing an InGaP optoelectronic confinement layer

We demonstrate and study a novel process for fabrication of GaAs-based self-aligned lasers based upon a single over-growth. A lattice-matched n-doped InGaP layer is utilized for both electrical and optical confinements. Single-lateral-mode emission is demonstrated initially from an In0.17Ga0.83 As double quantum well laser emitting similar to 980 nm. We then apply the fabrication technique to a quantum dot laser emitting similar to 1300 nm. Furthermore, we analyze the breakdown mechanism in our devices and discuss the limitations of index guiding in our structures

Characterizing bandgap gratings in GaAs: AlAs superlattice structures using interface phonons

Interface Raman modes were used to study quantum-well intermixing in GaAs : AlAs superlattice (SL) structures using room-temperature spatially resolved Raman spectroscopy. The intermixing was observed to degrade the interface mode intensity, which can be used as a sensitive indicator of the SL quality. This feature, along with spatially resolved photoluminescence, was used to investigate bandgap modulation in periodically intermixed bandgap gratings, fabricated using implantation induced disordering. Using interface modes instead of bulk-like modes is a promising avenue for characterizing SL structures that rely on intricate bandgap feature

Control of the band-gap shift in quantum-well intermixing using a germanium interlayer

Applied Physics Letters76121582-1584APPL

Control of the third-order nonlinearities in a GaAs/AlGaAs superlattice by ion implantation quantum well intermixing

Self-phase modulation was observed in GaAs/AlGaAs superlattice-core waveguides that were quantum well intermixed by ion implantation. The band gap was blue-shifted by 68 nm and the Kerr effect was suppressed by 67% after intermixing

Type-II quasi-phase-matched second-harmonic generation in domain-disordered semiconductor waveguides

Second-harmonic generation is demonstrated in periodically intermixed GaAs/AlGaAs superlattice waveguides by Type-II phase matching. Second-harmonic powers of 2.0 mu W were generated at fundamental phase matching wavelength of 1577.4 nm

Controlling third-order nonlinearities by ion-implantation quantum-well intermixing

The optical Kerr effect was measured by observing self-phase modulation in GaAs-AlGaAs superlattice-core waveguides modified by ion-implantation quantum-well intermixing. The band-gap energy was shifted by 68 nut for an implantation dose of 0.5 X 10(13) cm(-2) and annealing temperature of 775 degrees C. The Kerr effect was suppressed by up to 71% in the transverse-electric polarization after intermixing. A reduced polarization dependence of the self-phase modulation was observed after intermixin

Continuous wave second-harmonic generation using domain-disordered quasi-phase matching waveguides

Second-harmonic generation in domain-disordered quasi-phase-matched GaAs/AlGaAs superlattice-core waveguides was demonstrated using a continuous wave fundamental source. Output second-harmonic powers of up to 1.6 mu W were measured when on a Fabry-Perot resonance peak. Temperature-related bistable behavior was observed in both the fundamental and second-harmonic output when tuning either the input power or input wavelengt