Liquid Crystal Metasurfaces Are the Heart of New Lidar Technology

Lumotive, the Bill Gates-funded startup developing lidar systems for autonomous vehicles, has introduced a disruptive beam-steering technology that aims to significantly improve the performance, reliability, and cost of lidar systems for the emerging self-driving car industry. Initially targeting the robo-taxi market, Lumotive’s patented system uses Liquid Crystal Metasurfaces (LCM) and silicon fabrication to achieve unmatched manufacturing efficiency while delivering unprecedented range, resolution, and frame rate.

The key to the lidar system is the beam-steering technology enhanced by a unique combination of a large optical aperture (25 x 25 mm) that delivers long range, a 120° field-of-view with high angular resolution, and fast random-access beam steering.

Lumotive’s lidar system for autonomous vehicles: the beam steering uses Liquid Crystal Metasurfaces and semiconductor manufacturing to improve performance, reliability, and cost.

David R. Smith, the James B. Duke Distinguished Professor of Electrical and Computer Engineering at Duke University and a pioneer in metamaterials research, said these concepts have been traditionally applied to radio waves, but Lumotive has developed dynamically tunable metamaterials for optics.

“Lumotive’s beam-steering technology is the culmination of years of fundamental research into controlling electromagnetic waves using artificially structured metasurfaces,” Smith said. “Their development is a tremendous advance in metamaterials research, as well as a breakthrough technology that addresses pressing and unmet needs in lidar and other optical systems.”

LCM Chip

The success of Lumotive’s beam-steering technology lies with its lidar system enabled by LCM chips that can be integrated into small form-factor systems.

The LCM chips contain no moving parts and are fabricated using mature semiconductor manufacturing along with liquid crystal display packaging to enable a commercially viable lidar system with low cost, high reliability, and small size.

“The LCM chip is the holy grail of lidar, finally enabling beam steering using a semiconductor chip, but efficiently and over a large optical aperture that’s hundreds of times larger than a MEMS mirror or an optical phased array,” said Lumotive co-founder and CTO Gleb Akselrod. “Our large aperture is like having a bigger telescope, allowing us to see dramatically farther than other systems.”

Lidar is an important part of the equation because its 3D-sensing technology is already being employed by autonomous driving systems, as well as advanced driver assistance systems that help drivers stay in their lanes and provide for automatic braking and collision avoidance.

Lidar systems determine range by emitting laser light pulses and measuring the round-trip flight time for those pulses to travel to and reflect back from objects. A lidar system creates a 3D perceptual map, of its surroundings by scanning, or “beam steering,” laser pulses across its two-dimensional field-of-view, with the third dimension derived from the distance measured to an object at a given horizontal and vertical position. Lidar has proven critical for autonomous vehicles because the technology can accurately locate objects to within a few inches at ranges of hundreds of yards.