VCSEL were initially mainly used for data communications. In recent years, the rise of 3D sensing applications in consumer electronics, industry, and automobiles has brought a second wave of major opportunities for VCSELs. Nowadays, VCSEL applications are becoming wider and wider, including wearable devices, medical, augmented reality/virtual reality (AR/VR), drones, logistics, robotics, industrial security, occupant monitoring, gesture recognition, and LiDAR (LiDAR) etc.
VCSEL-based 3D imaging has surpassed traditional stereo vision solutions, mainly including structured light and time-of-flight (ToF) solutions and their hybrid applications. Traditional stereo vision uses two cameras with a known separation distance to shoot from different angles, and then uses algorithms to construct 3D images. The structured light scheme transforms the distortion of the captured light spot image into 3D information of the subject by projecting a known light spot pattern. The ToF scheme relies on measuring the round-trip time or phase difference between the laser pulse and the object to construct a 3D image of the scene or object.
Both structured light and ToF solutions need to use VCSEL to illuminate the target scene under a wide range of working conditions (including peak optical power and pulse parameters, etc.). Optimizing laser output power and efficiency, beam divergence angle, etc. are critical to VCSEL performance. In addition, VCSEL chip design and efficient integration in user-specific modules will also become the key to whether VCSEL can achieve more application introduction in the future. VCSELs are usually integrated into modules that include optical elements and/or drivers to create the required lighting configuration. Innovations in VCSEL design and integration can optimize packaging to improve device footprint and laser performance.
