High-power VCSEL lasers measurement method for beam divergence angle
Vertical-Cavity Surface-Emitting Laser(VCSEL)is distinguished by its ability to emit light beams perpen-dicular to the cavity surface.This unique characteristic allows multiple VCSEL lasers to be densely integrated on a sin-gle chip without requiring a significant amount of space.Additionally,VCSEL lasers utilize the reflective mirrors of a resonant cavity to enhance and amplify the light,leading to efficient light emission.Typically,the luminous efficiency of VCSEL lasers can range between 40％and 60％.Compared to traditional lasers,VCSELs are more apt to achieve high efficiencies.Due to their excellent integrability and high efficiency,VCSELs have found broad applications in fields such as 3D perception,automatic driving,and optical communication.Hence,the quality inspection of VCSEL lasers is becoming increasingly vital.As VCSEL lasers venture into the high-power domain,their light beam modes have evolved from fundamental mode to high-order mode.The beam has transitioned from a Gaussian-like beam to a Laguerre-Gaussian hollow ring beam.While traditional methods such as 1/e2 and D86 are quite accurate for measuring the divergence angle of Gaussian-like beams in fundamental mode,they exhibit notable discrepancies when applied to the Laguerre-Gaussian hollow ring beams in high-order mode.Given the widespread use of VCSEL lasers in crucial ar-eas like autonomous driving,the demand for precise beam measurements has also surged.Therefore,this article adopts the D4σ algorithm to measure the divergence angle of the Laguerre-Gaussian hollow ring beam and compares it with conventional methods like 1/e2 and D86.The results indicate that the new method enhances the accuracy of diver-gence angle measurements by up to 2.30％.
D4σ algorithmbeam qualitybeam divergence angleVCSELLaguerre-Gaussian hollow ring beam
万方数据
维普
