Design, fabrication, and nanosecond-pulse characterization of high-power-density multi-junction VCSEL arrays

This work presents the design, fabrication, and detailed characterization of a high-power-density 6-junction vertical-cavity surface-emitting laser (VCSEL) array operating under nanosecond-pulse conditions. The array demonstrates a high peak power of 136 W and a power density exceeding 2000 W/mm². By optimizing epitaxial structure through the incorporation of an extended cavity and a reduction in the thickness and number of oxide layers, high-order modes are effectively suppressed, leading to a low divergence angle of 18.5°-22.8°. Furthermore, we investigate the influence of duty cycle on output power, spectral properties, and far-field performance, uncovering non-negligible thermal effects even during short-pulse operation. These results offer valuable guidance for thermal management and driving strategies in the development of high-performance multi-junction VCSEL arrays for LiDAR and advanced sensing applications.