Second-harmonic generation from GaAs/AlAs multilayers in reflection geometry

Summary form only given. GaAs and AlGaAs have very large second-order susceptibilities. To achieve efficient frequency conversion, multilayers have been used to achieve quasi-phase matching (QPM). Although reflected-second-harmonic generation (SHG) in GaAs/Al/sub x/Ga/sub 1-x/As multilayers was initially studied, QPM in this geometry has not been achieved so far. Here, we report our results on detailed investigation of reflection-SHG from high-quality GaAs-AlAs multilayers. For the first time, to our knowledge, we have identified second- and third-order QPM peaks by measuring the spectrum of the reflection SHG. We have measured the dependence of the SH pulse energy on the pump polarization as well as incident angle.