MEMS phased array for high-speed, random access variable focusing and control for LIDAR and 3D imaging

Engineers in the Solgaard lab have developed a high-speed, random access grating light valve (GLV) for phase modulation to steer and focus light in LIDAR and 3D imaging applications. This MEMS-based phased array technology uses small voltages to control independently addressable silicon ribbons that act as a diffraction grating for a pulsed laser light. This enables beams to be steered to any of the possible positions from any other position and in any order with refresh rates up to 350 kHz.

Beam scanners using GLV have a large field of view (FOV) and are smaller, lower cost and more robust than conventional modulators. This optical remote sensing technology could enable LIDARs with unique capabilities for tracking objects at high speed for applications in autonomous control and machine learning and vision.

Phased Array for Random Access Scanning: Model of phased array with silicon ribbons in passive state (off) and active operation (amplitude and phase). By controlling the ribbon with small voltages, the device acts as a diffraction grating for pulsed laser light.

Stage of Development
The inventors have demonstrated proof of concept for random access of variable-depth focusing and steering of a non-patterned line with a high-speed linear MEMS phase modulator with 1088 electronically addressable elements (silicon nitride ribbons). This device was capable of random access scanning at 350 kHz in a Fourier regime and achieved 725 scan lines with a .9 degree field of view (FOV), with an expected far field response of 660 lines with an 18 degree FOV after magnification. Inventors have built a proof of concept 3D varifocal display. Further research extending device resolution and field of view will improve 3D imaging and demonstrate LIDAR imaging. The scanning and display principles are also being incorporated into a prototype microscope.