High gain signal amplification in an InSb transphasor at 77 K

We present experimental observations of the variations of the input-output characteristic of a nonlinear Fabry–Perot resonator as a function of initial detuning. The characteristics include regions with various differential gains, or show hysteresis with the width of the bistable region being variable. Operating the device as a transphasor (optical transistor), a signal of 3 μW can be amplified with a signal power gain of up to 104 with the device operating at 77 K and 1819 cm−1.