Ultrafast plasma mirrors in the microwave range

An experimental and numerical study of a laser-driven semiconductor mirror is detailed, which addresses two questions: whether a laser-induced semiconductor mirror is as good as a metal mirror in the microwave range and if so, at which value of photoconductivity such a metallic behavior sets in. A novel time-frequency analysis is used to investigate the properties of the mirror, based on measurements of average power transmitted through a microwave resonator. We demonstrate that a good macroscopic reflector can be realized through a semiconductor plasma, whose conductivity is orders of magnitude smaller than the one of a good metal. This non-trivial result is relevant for applications in which the mirror is requested to be switched on and off at a frequency of several gigahertz