Energy hot spots distribution on groove surface, elucidated by hybrid optical model in illuminated SOI photo-polarized-activated modulator

Abstract

A polarizer transistor sharing a groove filtering aperture was developed. In the device, entitled Silicon-On-Insulator Photo-Polarized Activated Modulator (SOIP2AM), one could think that the larger the V-groove, the higher is the absorbed illumination, and consequently the higher is the amount of new generated pairs of electrons-holes inside the device. In fact, the higher the illumination, the higher the destructive interference points inside the V-groove. Establishing a strong correlation between electrical and optical phenomena, two physical assumptions are presented. The first one is that observed “hot spots” (i.e. intense electrical field areas), are in fact the mirror of optical constructive interferences near the walls of the V-groove. The second assumption is that the closer the hot spots near the wall, the higher the generation of pairs of electrons-holes, since more absorbed photons. A new method, based on analytical hybrid optical model (Snell, Fresnel, Fourier, Energy Conservation), and numerical simulations, enabled to mathematically identify these phenomena, in order to optimize the modulator, as a function of several physical parameters such as the aperture angle, the groove’s depth, the groove’s shape (rectangular, triangular, rounded and parabolic), the light polarized direction, and the beam wavelength. Moreover, in order to optimize the absorption of the polarized illumination, several solutions are proposed. The present case study and proposed adapted solution can serve as a basis of generic approach in sensors’ activation towards optimized polarized beam absorption.