Anomalous refractive properties of a two-dimensional photonic band-gap prism

TL;DR

This paper investigates the optical response of a 2D photonic band-gap prism, revealing an unusual superprism effect at high frequencies with potential device applications, validated through numerical simulations and experimental comparisons.

Contribution

It introduces a novel analysis method for the optical properties of photonic crystal prisms, highlighting the superprism effect and providing a practical simulation approach.

Findings

Validation of the simulation approach with experimental data

Identification of an unusual superprism effect at high frequencies

Potential applications in photonic devices

Abstract

An analysis of the optical response of a triangular-shaped photonic band-gap prism is presented. Numerical simulations have been performed in the framework of multiple-scattering theory, which is applied considering spot illumination to avoid diffraction effects. First of all, refractive properties in the frequency range below the first TM band-gap are analyzed and compared with the available experimental data. It validates the approach employed and supports the predictions obtained in the frequency range above the gap. At these high frequencies we found an unusual superprism effect characterized by an angle- and frequency-sensitivity of the intensity of outgoing beams. We report several representative examples that could be used in device applications. The results are interpreted in terms of the corresponding semi-infinite photonic crystal, through the analysis of the coupling between external radiation and bulk eigenmodes, using the 2D Layer- Korringa-Kohn-Rostoker method. The procedure presented here constitutes a simple but functional alternative to the methods used until now with the same purpose.