Coherent Millimeter-Wave Generation by Heterodyne Conversion in Low-Temperature-Grown GaAs Photoconductors. (Reannouncement with New Availability Information)

摘要

An analysis has been carried out of optical heterodyne conversion with aninterdigitated-electrode photomixer made from low-temperature-grown (LTG) GaAs and pumped by two continuous-wave, frequency-offset pump lasers. The analytic prediction is in excellent agreement with the experimental results obtained recently on a photomixer having 1.0-micrometers-wide electrodes and gaps. The analysis predicts that a superior photomixer having 0.2-micrometers-wide electrodes and gaps would have a temperature-limited conversion efficiency of 2.0% at a low difference frequency, 1.6% at 94 GHz, and 0.5% at 300 GHz when connected to a broadband 100 load resistance and pumped at hv=2.0 eV by a total optical power of 50 mW. The predicted 3-dB bandwidth (193 GHz) of this photomixer is limited by both the electron-hole recombination time (0.6 ps) of the LTG-GaAs material and the RC time constant (0.5 ps) of the photomixer circuit.... LTG GaAs, Heterodyne conversion, Microwaves, Photoconductors.