Efficient intersubband-based SHG in semiconductor quantum wells

Abstract

Greatly enhanced intersubband-based nonlinearities in semiconductor multiple quantum wells (MQWs) are very attractive for efficient frequency conversion including second harmonic generation (SHG). However the phase-matching condition becomes crucial as one attempts to get high conversion efficiencies via increasing the interaction length. We report here on the efficient SHG of mid-infrared light, where a novel scheme was used to match the fundamental and second harmonic beams, i.e., to compensate for the natural dispersion of the waveguide bulk material, which otherwise leads to dephasing within 40 /spl mu/m. The structure studied consists of an active SHG MQW region placed between two phase matching (PM) regions. The active region incorporates 178 periods of repeated asymmetric InGaAs-InAlAs double quantum wells.