Properties of wideband resonant reflectors under fully conical light incidence

TL;DR

This study combines numerical modeling and experiments to show that fully conical light incidence enhances the angular tolerance and spectral performance of wideband resonant reflectors, with potential applications in efficient, material-sparse optical devices.

Contribution

It demonstrates that fully conical mounting improves the angular and spectral performance of wideband resonant reflectors compared to classical mounting, supported by both simulations and experiments.

Findings

Fully conical mounting increases angular tolerance of reflectors.

Numerical calculations show improved spectral performance in conic incidence.

Experimental verification confirms enhanced wideband reflectors in silicon across 1200-2400 nm.

Abstract

Applying numerical modeling coupled with experiments, we investigate the properties of wideband resonant reflectors under fully conical light incidence. We show that the wave vectors pertinent to resonant first-order diffraction under fully conical mounting vary less with incident angle than those associated with reflectors in classical mounting. Therefore, as the evanescent diffracted waves drive the leaky modes responsible for the resonance effects, fully-conical mounting imbues reflectors with larger angular tolerance than their classical counterparts. We quantify the angular-spectral performance of representative resonant wideband reflectors in conic and classic mounts by numerical calculations with improved spectra found for fully conic incidence. Moreover, these predictions are verified experimentally for wideband reflectors fashioned in crystalline and amorphous silicon in distinct spectral regions spanning the 1200-1600-nm and 1600-2400-nm spectral bands. These results will be useful in various applications demanding wideband reflectors that are efficient and materially sparse.