US 11,754,681 B2
LIDAR system with a multi-mode waveguide photodetector
Behsan Behzadi, Sunnyvale, CA (US); Omer P. Kocaoglu, Fremont, CA (US); Keith Gagne, Santa Clara, CA (US); Oguzhan Avci, Cupertino, CA (US); Neal N. Oza, Palo Alto, CA (US); and Mina Rezk, Haymarket, VA (US)
Assigned to Aeva, Inc., Mountain View, CA (US)
Filed by Aeva, Inc., Mountain View, CA (US)
Filed on Apr. 4, 2019, as Appl. No. 16/375,511.
Prior Publication US 2020/0319314 A1, Oct. 8, 2020
Int. Cl. G01S 7/481 (2006.01); G01S 7/491 (2020.01); G01S 17/32 (2020.01); G01S 17/58 (2006.01); G01S 17/89 (2020.01); G02B 27/30 (2006.01); G02B 27/28 (2006.01); G01S 17/34 (2020.01); G01S 7/4913 (2020.01)
CPC G01S 7/4817 (2013.01) [G01S 7/4811 (2013.01); G01S 7/4913 (2013.01); G01S 17/34 (2020.01); G01S 17/58 (2013.01); G01S 17/89 (2013.01); G02B 27/283 (2013.01); G02B 27/30 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A light detection and ranging (LIDAR) apparatus, comprising:
an optical source configured to emit an optical beam;
a polarization wave plate configured to transform a polarization state of the optical beam;
a lens configured to collimate the optical beam;
free space optics configured to:
receive a first portion of the optical beam as a target signal;
receive a second portion of the optical beam from the polarization wave plate as a local oscillator signal, wherein the polarization wave plate comprises a reflector or a coating to return the second portion of the optical beam; and
combine the target signal and the local oscillator signal;
a set of multi-mode (MM) waveguides; and
a demultiplexer comprising a dispersive element, the demultiplexer configured to:
disperse, via the dispersive element, each respective wavelength of the combined signal at a corresponding angle; and
reflect each respective wavelength of the combined signal to a corresponding MM waveguide of the set of MM waveguides.