By Ergun Canoglu, Ph.D. on July 28, 2021 | Leave a Comment
Chip scale LiDAR technologies are considered to significantly improve SWaP-C (Size, Weight, Power, and Cost) of a LiDAR system and lead to large-scale adoption of LiDAR devices for autonomous vehicles, ADAS L3/L4 vehicles and robotic applications.
Coherent LiDAR, also known as FMCW LiDAR technology leverages photonic integrated circuits developed for coherent fiber optic communication to enable chip-scale LiDAR devices. With the availability of silicon photonics-based PICs from CMOS foundries, coherent LiDAR chip designers now can fit thousands of LiDAR chips into a single wafer. However, these silicon chips attenuate the laser light intensity and have an upper limit for the maximum laser input power, which can limit the range of a Lidar system. These limitations can be avoided by strategically placing optical amplifiers into the optical circuitry.
Semiconductor Optical Amplifiers (SOAs) offer a unique advantage over fiber-based optical amplifiers when SWaP-C of a LiDAR system is considered. Unlike fiber amplifiers, SOAs can provide high optical output power for LiDAR applications, in 1-3mm long semiconductor chips. Fiber amplifiers on the other hand require few meters of fiber and a pump laser to provide similar optical amplification and power. In addition to their compact size, SOAs can be designed to be placed onto a silicon wafer containing the LiDAR optical circuitry. SOAs designed with flip-chip capability allow designers to strategically place amplification in the optical circuitry in the LiDAR chip to enable long-range and/or high-resolution sensing.
Today's SOAs can provide >200mW optical output power which can translate to >200m sensing range. When used alongside solid-state beam steering technology in the same silicon chip and narrow linewidth coherent lasers, high-power SOAs can enable chip-scale LiDAR devices.
With the ability to provide high optical power in a small footprint and wafer-scale integration capability, high-power SOAs are expected to lower SWaP-C characteristics of LiDAR designs and enable sensors for high-volume applications.
NeoPhotonics Corporation published this content on 28 July 2021 and is solely responsible for the information contained therein. Distributed by Public, unedited and unaltered, on 28 July 2021 21:56:04 UTC.