Intersubband All-Optical Limiter Based On Thermally Induced Intervalley Transfer

We propose an all-optical limiter based on the thermally induced intervalley transfer of electrons from Gamma-valley states with forbidden normal-incidence intersubband interactions to L-valley states which absorb strongly. Detailed modeling of the device performance in the short-pulse regime (less than or equal to 100 ns) yields that the output intensity for a limiter with only 10% insertion loss at low excitation levels will remain clamped over a dynamic range of 25-40.