Ab initio design and experimental confirmation of Fabry–Perot cavities based on freestanding porous silicon multilayers

Abstract

In this article, we report a hybrid quantum–classical design of Fabry–Perot multilayer cavities. Such design starts from an ab initio calculation of the dielectric function for each semiconducting layer with a specific atomic structure, followed by a study of wave scattering through the device using the transfer matrix method within the classical electromagnetic theory. This optical cavity consists of two multilayer reflectors separated by a single impurity layer, which is tuned to exhibit a resonant peak at the center of reflection band. The validation of this multiscale design was carried out on a freestanding nanostructured porous silicon multilayer film fabricated by electrochemical etching of a highly-doped p-type [100]-oriented crystalline Si wafer alternating two anodic current densities and finishing with a high current to separate the multilayer from the substrate. The measured infrared transmittance spectra are compared with those predicted from the hybrid design.