Lidar sensors work by bouncing laser light off surrounding objects to produce a three-dimensional “point cloud.” The first modern three-dimensional lidar was created for the 2005 DARPA Grand Challenge, a pivotal self-driving car competition. Today, many experts continue to see lidar as a key enabling technology for self-driving cars.

That original 2005 lidar, made by a company called Velodyne, contained a vertical array of 64 lasers that spun around 360 degrees. Each laser had to be carefully aligned with a corresponding detector. This complexity contributed to prices as high as $75,000. Today, high-end lidars still cost tens of thousands of dollars.

There are now dozens of startups trying to build cheaper lidar. Many of them try to reduce costs by using a single laser beam that’s scanned in a two-dimensional pattern.