New type of porous silicon-based optical microcavity biosensor using a thin metal film.

This paper proposes a new type of a porous silicon-based optical microcavity biosensor using a thin metal layer. The detection system was composed of a bottom distributed Bragg reflector (DBR) of porous silicon as an overlayer. After changing the refractive index of the defect layer through interactions of biomaterial, a thin metal layer was deposited onto the defect layer as a top mirror to form a complete microcavity. The optical sensitivity of the new microcavity biosensor with a single DBR and metal mirror can still be high only with the level f modification of a single porous layer, which is comparable to that of the conventional microcavity biosensor with two DBRs, where the modification of multiple porous layers is required. The results of the numerical simulation for the cavity quality and sensitivity of the proposed microcavity biosensor were provided. [ABSTRACT FROM AUTHOR]