Low-Temperature-Grown GaAs Photoconductor with High Dynamic Responsivity in the Millimeter Wave Range

The responsivity of a low-temperature-grown GaAs photoconductor using a metallic mirror Fabry–Pérot cavity has been measured up to 48 GHz thanks to an optical mixing experiment. For a bias voltage of 8 V, it reaches 0.18 A/W and is constant over the whole frequency range. Furthermore, an output power P out of ∼100 µW has been measured at 48 GHz with an optical pump P opt of 11.2 mW. The photomixing efficiency, η ph = P out / P opt 2 , is improved by a factor of about 60 as compared to the previous works.