Investigation on GaN-Based Membrane Photonic Crystal Surface Emitting Lasers.

Jingtong Bin,Minjia Meng,Wei Shen,Qifa Liu,Kerui Feng

doi:10.3390/ma15041479

Abstract

A GaN-based blue photonic crystal surface emitting laser (PCSEL) featured with membrane configuration was proposed and theoretically investigated. The membrane dimension, photonic crystal (PhC) material, lattice constant and thickness were studied by RCWA (Rigorous Coupled Wave Analysis), FDTD (Finite Difference Time Domain) simulations with the confinement factor and gain threshold as indicators. The membrane PCSEL’s confinement factor of active media is of 13~14% which is attributed to multi-pairs of quantum wells and efficient confinement of the mode in the membrane cavity with air claddings. The excellent confinement factor and larger Q factor of resonance mutually contribute to the lower gain threshold of the design (below 400 cm−1 for GaN-PhC with 100 nm thick top and bottom GaN layer, 40 nm hole radius and 40 nm depth). The PhC confinement factor exceeds 13% and 6% for TiO2-PhC with 80 nm and 60 nm PhC thickness and 20 nm and 40 nm distance between PhC and active media, respectively. It is around two times larger than that of GaN-PhC, which is attributed to the higher refractive index of TiO2 that pulls field distribution to the PhC layer.

Highlights

GaN-based blue lasers play a critical role in optical communications, especially underwater communication [1,2]
Route I: First, the wafer with p-contact was bonded with the PDMS stamp; the silicon or sapphire substrate was released by dry etching or laser lift-off; GaN thinning, photonic crystal (PhC) and n-contact fabrication were performed
We investigated TiO2 as PhCs materials here to give a comparable design for the membrane GaN photonic crystal surface emitting laser (PCSEL)

Summary

Introduction

GaN-based blue lasers play a critical role in optical communications, especially underwater communication [1,2]. Based on the outstanding properties of GaN laser diodes [3,4,5,6], they have been widely used in high-density data storage, laser display, material processing and biomedical devices. The first semiconductor photonic crystal surface emitting laser (PCSEL) was realized in an InP-based system in 1999 [7]. Compared with vertical cavity surface-emitting lasers (VCSELs), it does not need the highly reflective Bragg mirror, which is very difficult to implement in a GaN-based material system [16]

Methods

Results

Conclusion