Invention:
This technology is a system and method for a wide field of view micro-electrical mechanical (MEMS)-based beam steering device that uses spatial light modulation to suppress problematic effects like DC and side lobe diffraction in applications like LIDAR.
Background:
Laser beam steering is an indispensable feature of light detection and ranging (LIDAR) systems. Diffractive beam steering offers a low-inertia steering mechanism that is inherently more reliable than purely mechanical methods.
In this approach, the phase of the laser is modulated in a pixelated pattern. The phase tilt induced by each pixel alters the wavefront of the modulated laser, causing it to propagate along a direction perpendicular to the phase front. However, the method has a limited steering angle, which is restricted by the wavelength-to-pixel ratio.
For a wide field of view, the pixel pitch must be less than half of the wavelength. A critical factor in laser beam steering is the suppression of side-lobes, which are a result of the diffraction of laser light towards unintended directions.
In general, steering a laser beam using a pixelated diffractive element is prone to side-lobes, diffraction towards unintended directions, and 0th order DC diffraction, which causes the laser light to diffract towards the direction of specular reflection.
Applications:
- LIDAR
- Beam steering
- Spatial light modulation
- Micro-electrical mechanical systems (MEMS)
Advantages:
- DC suppression
- Side lobe suppression
