US 9,810,786 B1
Optical parametric oscillator for lidar system
David Welford, Danvers, MA (US); Martin A. Jaspan, Somerville, MA (US); Jason M. Eichenholz, Orlando, FL (US); Scott R. Campbell, Sanford, FL (US); Lane A. Martin, Sunnyvale, CA (US); and Matthew D. Weed, Winter Park, FL (US)
Assigned to Luminar Technologies, Inc., Portola Valley, CA (US)
Filed by LUMINAR TECHNOLOGIES, INC., Portola Valley, CA (US)
Filed on Mar. 16, 2017, as Appl. No. 15/461,380.
Int. Cl. G01S 3/08 (2006.01); G01S 17/10 (2006.01); G01S 7/484 (2006.01)
CPC G01S 17/10 (2013.01) [G01S 7/484 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A lidar system comprising:
a pump laser configured to produce pulses of light at a pump wavelength;
an optical parametric oscillator (OPO) comprising an OPO medium configured to:
receive the pump pulses from the pump laser;
convert at least part of the received pump pulses into pulses of light at a signal wavelength and pulses of light at an idler wavelength; and
emit at least a portion of the signal pulses;
a scanner configured to scan the emitted signal pulses of light across a field of regard;
a receiver configured to detect at least a portion of the scanned pulses of light scattered by a target located a distance from the lidar system, wherein:
an output beam of the lidar system comprises the emitted signal pulses of light which are scanned across the field of regard;
an input beam of the lidar system comprises the portion of the scanned pulses of light detected by the receiver; and
the input and output beams are substantially coaxial;
an overlap mirror configured to overlap the input and output beams so that they are substantially coaxial, wherein the overlap mirror comprises:
a hole, slot, or aperture which the output beam passes through; and
a reflecting surface that reflects at least a portion of the input beam toward the receiver; and
a processor configured to determine the distance from the lidar system to the target based at least in part on a round-trip time of flight for an emitted pulse of light to travel from the lidar system to the target and back to the lidar system.