Efficient light coupling from integrated single-mode waveguides to supercollimating photonic crystals on silicon-on-insulator platforms

TL;DR

This paper presents a practical method for efficiently coupling light from single-mode waveguides to supercollimating photonic crystals on silicon-on-insulator platforms, achieving high transmission and low reflection.

Contribution

It introduces a novel waveguide-PCS coupling scheme with boundary truncation to enhance impedance matching and efficiency.

Findings

Transmission efficiencies up to 96%

Reflections below 0.2% at 1.55 microns

Effective integration on silicon photonic chips

Abstract

We propose a practical and efficient solution for the coupling of light from integrated single-mode waveguides to supercollimating planar photonic crystals on conventional silicon-on-insulator platforms. The device consists of a rib waveguide, designed to sustain spatially extended single-modes and matched to a supercollimating photonic crystal, which has been truncated at its boundary to improve impedance matching between the two photonic components. Three-dimensional simulations show transmission efficiencies up to 96 % and reflections below 0.2 % at wavelengths close to 1.55 microns. This approach constitutes a significant step toward the integration of supercollimating structures on photonic chips.