Monolithic Millimeter Wave Optical Receivers using MSM photodetectors and SMODFET's

Integrating MSM photodetectors and SMODFET's, single stage millimeter wave optical receiver circuits were fabricated monolithically on an MBE grown GaAs wafer. The photodetector layer was designed for the maximum absorption of 770nm light. The SMODFET's utilized 120Å In_0.2Ga_0.8As channel. The circuits were designed for 44GHz operation. The measurement with beating Ti-Sapphire lasers and a spectrum analyzer on the optical receiver circuits showed 3dB gain over a photodetector at 39GHz, which was the limit of the measurement. The calculated gain of the circuit was 6.6dB over the photodetector and 5.7dB including photodetector signal drop at 44GHz.