Optical sensing of chemical compounds using porous silicon microcavities

Summary form only given. In this work, we present some very interesting results about the detection of chemical compounds by using porous silicon microcavities (PSMs). The microcavity is constituted by a Fabry-Perot cavity confined between two Distributed Bragg Reflectors (DBRs). When the PSM is exposed to vapors or dipped in liquid organic solvent a repeatable and completely reversible change in the reflectivity spectrum is observed. The substitution of air with organic species in the pores determines an increasing of the average refractive index of the microcavity, resulting in a marked red-shift of its characteristic peak.