Optimization of element structure in 980 nm high-power vertical-cavity surface-emitting laser array

The reflectivity of a Distributed Bragg Reflector (DBR) was optimized to improve the output characteristics of a 980 nm Vertical-cavity Surface-emitting Laser (VCSEL) array. The relationship among the reflectivity of N-DBR, threshold current, output power and wall-plug efficiency was analyzed. Then, the reflectivity of N-DBR was adjusted to achieve higher slope efficiency in a relative low threshold current and to improve the overall output characteristics of the VCSEL array. After N-DBR reflectivity optimization, the developed VCSEL array including 64 elements can offer a CW output power of 2.73 W under the injected current of 6 A and a pulse output power of 115 W under the pulse drive current of 130 A, a pulse width of 100 ns and a repetition frequency of 100 Hz. Furthermore, the VCSEL array including 300 elements can provide a CW output power of 5.26 W under the injected current of 18 A. It concludes that the performance of VCSEL array has been improved by N-DBR reflectivity optimization.