Microwave-assisted far-infrared photoconductivity in high-purity GaAs

We have observed, for the first time, microwave-assisted photoconductivity in high purity GaAs. The enhancement of response appears to be dictated by two distinct mechanisms. First, a broadband enhancement which is believed to be due to detrapping of the free carriers and, therefore, increased photoconductive gain. Secondly, microwave-ionization of the excited states. We expect that both of these mechanisms contribute very little, if any, to the detector noise and, therefore, improve the detector's NEP. In this paper, we report the results of our preliminary tests showing broadband enhancement in response and an indication of enhancement of the excited-state response. Further investigation is currently underway.