Study of an Epitaxial Regrowth Process by MOCVD for Photonic-Crystal Surface-Emitting Lasers

Abstract

We study a metal organic chemical vapor deposition regrowth process for electrically driven photonic-crystal surface-emitting lasers (PCSELs). The photonic-crystal (PC) structure consisting of air voids embedded in semiconductor materials is fabricated on the topmost p-GaAs layer of a base-epitaxial wafer followed by the regrowth of a p-Al0.45GaAs layer and a p+-GaAs contact layer, consecutively. The effect of both ex situ and in situ surface treatment before regrowth processes together with the regrowth parameters are investigated. The O2 plasma treatment, one of the ex situ treatment process steps, is found to be critical for the surface condition. A flat surface with retained air voids is obtained with proper surface treatment and epitaxial growth condition, and the electrically pumped PCSELs are successfully demonstrated. Moreover, the optimized regrowth condition is also applicable to various PC topologies to enhance the optical output performance.

Small signal modulation of photonic crystal surface emitting lasers

“…Historically PCSELs have been formed by wafer fusion, but these devices suffered from low output powers due to defect states in the PC region as a result of regions of discontinuous crystallinity formed during the wafer fusion process 7 – 9 . More recently our group 10 – 12 along with several others have demonstrated PCSELs formed by epitaxial regrowth 13 – 17 . The move to epitaxial regrowth by metalorganic vapour phase epitaxy (MOVPE) has demonstrated a pathway to high volume production of highly reliable devices leveraging all the knowledge gained over many years of InP DFB development.…”

A Simple Method to Build High Power PCSEL Array with Isolation Pattern Design

“…Many efforts have been made to increase the output power of PCSELs. They include buried air hole photonic crystal structures, introducing DBR into a PCSEL structure, filling factor optimization, and nonsymmetric photonic crystal design [17][18][19][20][21][22]. As well as these, PCSELs are especially suitable for power scaling [23,24] because of the in-plane oscillation behavior and the absence of catastrophic damage.…”