Millimeter-scale and large-angle self-collimation in a photonic crystal composed of silicon nanorods

TL;DR

This paper demonstrates large-angle self-collimation in silicon nanorod photonic crystals, enabling narrow, divergence-free light beams over significant distances suitable for on-chip optical communication.

Contribution

It reports the experimental observation of large-angle self-collimation in nanorod-based photonic crystals, a novel phenomenon for integrated photonics.

Findings

Propagation length of 0.4 mm at 1540-1570 nm wavelength range

Effective self-collimation over a wide range of incident angles

Potential for on-chip optical interconnection applications

Abstract

We report the observation of a large-angle self-collimation phenomenon occurring in photonic crystals composed of nanorods. Electromagnetic waves incident onto such photonic crystals from directions covering a wide-range of incident angles become highly localized along a single array of rods, which results in narrow-beam propagation without divergence. A propagation length of 0.4 mm is experimentally observed over the wavelength range of 1540 nm to 1570 nm, even in the large incident angle case, which is a very considerable length scale for on-chip optical interconnection.