Oscillation characteristics of electrically-pumped vertical external cavity surface emitting lasers

Abstract

The oscillation characteristics of 980 nm electrically-pumped vertical-external-cavity surface-emitting laser (EP-VECSEL) with periodic gain structure active region of InGaAs/GaAsP quantum well was analyzed theoretically and experimentally. The relationship between the DBR & external cavity mirror reflectivity and the oscillating characteristic characteristics of the EP-VECSEL with coupled cavity was simulated. Furthermore, based on the results of simulation, the device structure was optimized. EP-VECSEL devices with different external cavity reflectivity were fabricated and the continuous-wave (CW) oscillation output characteristics were studied. The results of experiment indicated that the threshold current of the 300 μm-device with 90% external mirror reflectivity was 1.2 A and its output power was 270 mW while under injected current of 4A; the output power of the 300 μm-device with 95% external mirror reflectivity was 150 mW at 4 A of injected current and the threshold current was 0.9 A. The experimental results were in good agreement with theoretical analysis, indicating that the model using in this article is suitable for the optimization of EP-VECSEL's oscillation characteristics.