Multiple beam, single mems lidar

Abstract

Various technologies described herein pertain to multiple beam, single mirror lidar. A multiple beam, single mirror lidar system can include a 2D MEMS mirror and a photonic integrated circuit. The photonic integrated circuit includes a plurality of lidar channels, each including a transmitter and a receiver. In the photonic integrated circuit, the lidar channels are directed at a common point on the 2D MEMS mirror. The lidar channels are oriented with relative offset angles. Thus, the lidar channels output beams that are directed at the common point on the 2D MEMS mirror and are oriented with relative offset angles.

What is claimed is: 
     
         1 . A multiple beam, single mirror lidar system, comprising:
 a movable mirror; and   a photonic integrated circuit, comprising:
 a first waveguide configured to guide a first beam towards the movable mirror; and 
 a second waveguide configured to guide a second beam towards the movable mirror; 
 wherein the first waveguide and the second waveguide are configured to guide the first beam and the second beam towards common point on the movable mirror with a relative offset angle. 
   
     
     
         2 . The multiple beam, single mirror lidar system of  claim 1 , wherein the movable mirror is a two-dimensional (2D) micro-electro-mechanical systems (MEMS) mirror. 
     
     
         3 . The multiple beam, single mirror lidar system of  claim 1 , the photonic integrated circuit further comprising:
 a first lidar channel, the first lidar channel comprises a first transmitter and a first receiver, wherein the first waveguide is configured to guide the first beam from the first transmitter towards the common point on the moveable mirror and to guide a first return beam from the movable mirror to the first receiver; and   a second lidar channel, the second lidar channel comprises a second transmitter and a second receiver, wherein the second waveguide is configured to guide the second beam from the second transmitter towards the common point on the movable mirror and to guide a second return beam from the movable mirror to the second receiver.   
     
     
         4 . The multiple beam, single mirror lidar system of  claim 1 , the photonic integrated circuit further comprising:
 a signal processor, the signal processor is configured to:
 receive a first electrical signal from the first receiver based on the first return beam and a second electrical signal from the second receiver based on the second return beam; and 
 derive distance data to one or more targets based on at least the first electrical signal and the second electrical signal. 
   
     
     
         5 . The multiple beam, single mirror lidar system of  claim 1 , wherein the first waveguide and the second waveguide are formed of one or more of silicon (Si), silicon dioxide (SiO2), silicon nitride (Si3N4), gallium arsenide (GaAs), indium phosphide (InP), or lithium nitrate (LiNO3). 
     
     
         6 . The multiple beam, single mirror lidar system of  claim 1 , wherein the relative offset angle is fixed. 
     
     
         7 . The multiple beam, single mirror lidar system of  claim 1 , further comprising:
 a single laser source, the single laser source is configured to generate an optical input; and   a splitter, the splitter is configured to split the optical input such that the first beam is inputted to the first waveguide and the second beam is inputted to the second waveguide.   
     
     
         8 . The multiple beam, single mirror lidar system of  claim 1 , wherein the relative offset angle is between 0 degrees and 30 degrees mechanical. 
     
     
         9 . The multiple beam, single mirror lidar system of  claim 1 , wherein the first waveguide terminates with a first structural component to couple the first beam to free space and the second waveguide terminates with a second structural component to couple the second beam to the free space. 
     
     
         10 . The multiple beam, single mirror lidar system of  claim 9 , wherein the first structural component comprises one of an edge coupler, a taper, or a grating coupler. 
     
     
         11 . The multiple beam, single mirror lidar system of  claim 1 , wherein the first waveguide and the second waveguide are oriented on the photonic integrated circuit at the relative offset angle. 
     
     
         12 . The multiple beam, single mirror lidar system of  claim 1 , wherein the relative offset angle is in an elevation direction. 
     
     
         13 . The multiple beam, single mirror lidar system of  claim 12 , wherein a tilt of the movable mirror in the elevation direction is limited relative to a maximum tilt in the elevation direction. 
     
     
         14 . The multiple beam, single mirror lidar system of  claim 1 , wherein the relative offset angle is in an azimuthal direction. 
     
     
         15 . A multiple beam, single mirror lidar system, comprising:
 a moveable mirror; and   a photonic integrated circuit, comprising:
 a first lidar channel; and 
 a second lidar channel; 
 wherein the first lidar channel and the second lidar channel are directed at a common point on the movable mirror and are oriented with a relative offset angle. 
   
     
     
         16 . The multiple beam, single mirror lidar system of  claim 15 , wherein the relative offset angle is in an elevation direction. 
     
     
         17 . The multiple beam, single mirror lidar system of  claim 16 , wherein a tilt of the movable mirror in the elevation direction is limited relative to a maximum tilt in the elevation direction. 
     
     
         18 . The multiple beam, single mirror lidar system of  claim 15 , wherein the relative offset angle is in an azimuthal direction. 
     
     
         19 . The multiple beam, single mirror lidar system of  claim 18 , wherein a tilt of the movable mirror in the azimuthal direction is limited relative to a maximum tilt in the azimuthal direction. 
     
     
         20 . A method performed by a multiple beam, single mirror lidar system, comprising:
 outputting beams from a plurality of transmitters, the beams being directed at a common point on a movable mirror and oriented at differing angles relative to each other;   actuating the movable mirror in two axes to scan the beams over a field of view in an environment;   collecting return beams from the environment responsive to the beams; and   generating a point cloud of data based on the return beams as collected.