Mechanical cleaving method for large-size mirror-like facets in high-power semiconductor lasers

The laser bar, a critical component in advancing laser technology, has seen widespread application across various high-power fields. However, its operational reliability and output power are often constrained by facet damage and limited facet length. Traditional methods for fabricating mirror-like facets face challenges in achieving large-size facets without defects. This study introduces a novel mechanical cleaving method to produce large-size, mirror-like facets for GaAs-based high-power laser bars. Finite element simulations were employed to investigate the proposed cleaving approach, followed by experimental trials to validate the findings. The results indicate that surface and subsurface damages are more likely to occur at the starting position of the scribed groove, yet mirror-like facets with a surface roughness of 0.45 nm and lengths up to 11 mm were successfully achieved. The research demonstrates that scribing depth significantly impacts surface quality, while scribing speed has minimal influence. This study provides valuable insights into the fabrication of large-size, high-quality facets, contributing to the development of more reliable and efficient high-power semiconductor lasers.