Superheterodyne microwave receiver of modulated optical radiation

The dependence of the difference-frequency component and of the constant current component on the heterodyne signal voltage was studied experimentally in the frequency bands 1-30 mHz and 0.3-5 mHz. A He - Ne laser was used as a monochromatic light source. The heterodyne voltage was delivered to a special system of external electrodes. It is concluded that highly sensitive receivers of microwave modulated optical radiation, operating on the superheterodyne principle, can be created by using standard photomultipliers. The sensitivity of such a system was studied.