Multiparametric gas sensors with porous silicon optical microcavities

We show that porous silicon optical microcavities can be effectively used as multiparametric gas sensors. Beside the electrical conduction, interesting gas-sensing parameters of porous silicon microcavities are the photoluminescence intensity and the spectral position of the resonance cavity peak, which depends on the index of refraction of the surrounding gas. The dynamic response of the peak shift is also discussed.