Theoretical analysis of an anisotropic metal–semiconductor–metal optoelectronic mixer

Abstract

We present a detailed study of the optoelectronic mixing effect in metal–semiconductor–metal detectors. Both analytical and numerical results are presented and the anisotropic effect is included in the calculations. Under transient bias voltage, the device shows two transient current responses: a fast one related to the displacement current and a slow one related to removal of carriers from the device. The mixing efficiency of the device increases with an increase in applied ac voltage and decreases with an increase in ac frequency. For anisotropic devices, rectification current exists. This rectification current varies not only with the ac voltage and optical power, but also with the ac frequency. This variation in current results in a self-clutter signal being observed in the experiments.