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.

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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.