Polarization control of defect modes in three-dimensional woodpile photonic crystals

Michael J Ventura,Min Gu

doi:10.1364/oe.16.009112

Abstract

The symmetry of a Fabry-Perot-like planar cavity embedded within a three-dimensional (3D) woodpile photonic crystal prevents the observation of polarization effects. In this letter we propose a geometry to break the degeneracy of the Fabry-Perot-like cavity modes by introducing asymmetry. The introduction of a one-dimensional (1D) lattice to the centre of a planar cavity allows for distinct modes parallel (TE) and perpendicular (TM) to the layer. This hybrid 3D-1D-3D lattice structure exhibits a pronounced increase in the quality-factor, and in particular shows an increase of up to 50% more than that of a planar cavity for TM modes.

Highlights

The ability to manipulate light on a scale comparable to its wavelength is the key to the development of the generation of optical devices
The symmetry of a Fabry-Perot-like planar cavity embedded within a three-dimensional (3D) woodpile photonic crystal prevents the observation of polarization effects
In this letter we propose a geometry to break the degeneracy of the Fabry-Perot-like cavity modes by introducing asymmetry

Summary

Introduction

The ability to manipulate light on a scale comparable to its wavelength is the key to the development of the generation of optical devices. Three-dimensional (3D) PCs, in particular the woodpile lattice is attractive due to its ability to provide directional or complete photonic bandgaps, allowing for the rigorous control of photons in all directions [3]. The implementation of this lattice as a platform for the development of optical devices is limited due to its polarization insensitivity. In this paper we show that the degenerate defect mode in a simple planar cavity that exhibits no polarization effects in the band diagram can be broken by introducing a one-dimensional (1D) lattice within the planar cavity This hybrid 3D-1D-3D lattice allows for two independent modes. Varying the period of the 1D lattice results in an increase in the quality factor of the defect modes

Proposed hybrid 3D-1D-3D lattice

Experimental verification

Findings

Conclusion