Vertical-Cavity Surface-Emitting Laser

A semiconductor laser that emits light perpendicular to the chip surface, a common light source in depth cameras and lidar.

The VCSEL is a type of semiconductor laser, proposed in 1977 by Kenichi Iga at the Tokyo Institute of Technology. An ordinary edge-emitting laser emits light from the side of a cleaved chip; a VCSEL instead sandwiches a light-emitting layer between two distributed Bragg reflector mirrors, top and bottom, so light exits perpendicular to the chip surface. This means it can be tested across a whole wafer before dicing, tens of thousands can be produced from one wafer at once, and it’s easy to arrange into a 2D array — giving low cost and good consistency. In embodied-AI-relevant hardware, VCSELs are the core of many active infrared light sources: the structured-light dot projector behind iPhone Face ID, time-of-flight (ToF) depth cameras, and lidar in phones and cars all commonly use VCSELs as their light source.

ExampleInside a structured-light depth camera, a VCSEL array projects thousands of infrared dots onto an object, and the camera computes depth at each point from how far its dot has shifted.

Also called

VCSEL, Surface-Emitting Laser

Related

Structured Light · Speckle Structured Light · Time of Flight · LiDAR · Single-Photon Avalanche Diode · Depth Camera

Sources

Vertical-cavity surface-emitting laser - Wikipedia