source: sciencedaily ai: mit’s new lidar chip could give self-driving cars a wider view
level: technical
mit researchers built a new silicon-photonics lidar chip that steers a light beam electronically across a wide field of view without any moving parts. the chip uses an integrated optical phased array, a group of antennas that emit light. by adjusting the phase of light sent to each antenna, the beam direction changes. previous chip-based lidar systems had a narrow view because placing antennas close together caused crosstalk, where neighboring antennas interfere and scramble signals. spreading antennas apart reduced interference but created grating lobes, extra beam copies that limit the scanning range and cause false detections.
the mit team solved this by designing a repeating set of three antennas with different shapes, widths, and corrugation patterns. these differences give each antenna a distinct propagation coefficient, so they do not couple strongly even when placed close together. the antennas were also engineered to emit light with the same intensity, angle, and steering behavior despite their geometric differences. the researchers developed electromagnetic theory to guide the design and then fabricated and tested the chip.
in experiments, the new array reduced crosstalk from about 100% in a standard design to roughly 1%. it produced a single clean beam and steered it across a broad field of view with no grating lobes. this advance could lead to smaller, more durable lidar sensors for autonomous vehicles, drones, and industrial monitoring. the team plans to extend the viewing range further and explore another wide-field approach discovered during the work.
why it matters: this chip enables compact, solid-state lidar with wide scanning and low noise, making autonomous systems safer and more practical for real-world use.
source: sciencedaily ai: mit’s new lidar chip could give self-driving cars a wider view