GaAs optoelectronic mixer operation at 4.5 GHz

Abstract

Optoelectronic heterodyne detection of high-frequency intensity modulation signals using a GaAs photoconductive mixer is reported. Flat response for optical modulation frequencies up to 4.5 GHz is observed for downconversion to a 500-MHz intermediate frequency using a low power local oscillator. Heterodyne responsivity was enhanced significantly over direct detection with the same photoconductive detector due to improved contact performance under RF bias.