Waymo Patents a Lens Coating That Cuts Light Loss in Its Self-Driving Car Sensors

By Patentlyze Team · Updated Jul 21, 2026

Waymo is patenting a small but carefully engineered lens designed to capture laser light more cleanly inside its self-driving car sensors, with a special coating that stops light from bouncing back the wrong way.

What Waymo's anti-reflection LiDAR lens actually does

Think of a LiDAR sensor as a very precise flashlight that maps the world around a car by firing thousands of tiny laser pulses per second. Getting those pulses to travel exactly where you want them, without losing energy to stray reflections or scattering, is harder than it sounds.

Waymo's patent describes a lens that sits between the laser source and a light-carrying channel called a waveguide. The lens has a curved surface on both sides (like a classic magnifying glass) and a flat edge used to mount it in exactly the right position. Critically, the curved surface that faces the laser gets a special anti-reflection coating, which stops a portion of the laser light from bouncing back instead of passing through.

It also performs a job called fast axis collimation, which essentially means it takes the light spreading out from a laser in a fan shape and squeezes it into a tighter, straighter beam. The result is less wasted light and a more reliable signal making it to the waveguide.

How the dual-convex lens routes laser light to the waveguide

The patent describes an optical system made up of three main parts: a light emitter (a laser), an optical waveguide (a channel that guides light from one place to another, like a fiber-optic cable), and a lens sitting between the two.

The lens has a distinctive shape: two convex surfaces (both curving outward, one facing the laser and one facing the waveguide) plus a flat surface that acts as a mounting base, letting engineers attach the lens to a substrate in a consistent, repeatable position.

The key optical function is fast axis collimation (FAC). Lasers used in LiDAR emit light that spreads out in an asymmetric cone, much wider in one direction than the other. The FAC lens compresses that wide spread into a narrower, more parallel beam so it can be efficiently coupled into the waveguide without losing energy to clipping or divergence.

The anti-reflection (AR) coating on the first convex surface addresses a separate problem: every time light crosses the boundary between air and glass, some of it reflects backward. That lost light reduces overall system efficiency and can create internal noise. The AR coating suppresses that reflection, letting more of the laser's output pass through into the lens and on to the waveguide.

What this means for self-driving LiDAR performance

LiDAR sensors are among the most expensive and mechanically complex parts of any self-driving vehicle. Every fraction of a percent of laser power that gets lost to stray reflections or beam spreading is power that has to be compensated for elsewhere, either with a stronger laser (more heat, more cost) or accepted as reduced range and accuracy.

For Waymo, which builds its own sensor hardware in-house, optimizing individual optical components like this lens is exactly the kind of incremental engineering that compounds into meaningful system-level performance. Better light coupling means longer detection range, cleaner point clouds, and potentially cheaper sensors over time. This is quiet, foundational work rather than a flashy new capability, but it's the type of detail that separates production-grade sensor hardware from prototype gear.

Editorial commentary on a publicly published patent application. Not legal advice.