Enhanced transmission and beaming of light via photonic crystal surface modes

TL;DR

This paper demonstrates that by engineering surface corrugations on photonic crystals, one can effectively control light transmission and beaming, enabling collimation and efficient coupling of light into waveguides.

Contribution

It introduces a theoretical method to manipulate surface modes in photonic crystals for improved light collimation and coupling.

Findings

Surface corrugation can induce radiation of surface modes.

Engineered surface indentations enable collimation of exiting light.

Surface modifications facilitate efficient free-space to waveguide coupling.

Abstract

Surface modes are generally believed to be an undesirable feature of finite photonic crystals (PC), unlike point or line defect modes. However, it is possible to make the surface mode radiate by appropriate corrugation of the PC interface. In this paper we show theoretically that the coherent action of these surface indentations can be engineered to collimate within a few degrees the light exiting a PC waveguide, or to funnel light coming from free space into the waveguide.