Single-mode InGaAs submonolayer quantum dot photonic crystal VCSELs

Abstract

An InGaAs submonolayer ( SML) quantum dot photonic crystal vertical-cavity surface-emitting laser ( QD PhC-VCSEL) for fibre-optic applications is demonstrated for the first time. The active region of the device contains three InGaAs SML QD layers. Each of the InGaAs SML QD layers is formed by alternate deposition of InAs (< 1 ML) and GaAs. Single-fundamental-mode CW output power of 3.8 mW at 28 mA has been achieved in the 990 nm range, with a threshold current of 0.9 mA. A side-mode suppression ratio ( SMSR) larger than 35 dB has been observed over the entire current operating range.