Beam shaping for ultra-small vertical cavity surface emitting laser (vcsel) arrays

Abstract

A laser array includes a plurality of laser diodes arranged and electrically connected to one another on a surface of a non-native substrate. Respective laser diodes of the plurality of laser diodes have different orientations relative to one another on the surface of the non-native substrate. The respective laser diodes are configured to provide coherent light emission in different directions, and the laser array is configured to emit an incoherent output beam comprising the coherent light emission from the respective laser diodes. The output beam may include incoherent light having a non-uniform intensity distribution over a field of view of the laser array. Related devices and fabrication methods are also discussed.

1 . A light detection and ranging (LIDAR) apparatus, comprising:
 an emitter array comprising emitter elements that are configured to output respective optical signals to illuminate a field of view, wherein respective subsets of the emitter elements are electrically connected to one other anode-to-cathode on a surface of a non-native substrate; and   at least one optical element that is configured to divert the respective optical signals output from the emitter elements positioned at respective regions of the emitter array to different portions of the field of view.   
     
     
         2 . The LIDAR apparatus of  claim 1 , wherein the respective optical signals define an output beam having a non-uniform intensity distribution over the field of view. 
     
     
         3 . The LIDAR apparatus of  claim 2 , wherein the at least one optical element comprises respective regions having different optical characteristics. 
     
     
         4 . The LIDAR apparatus of  claim 3 , wherein the respective regions of the at least one optical element are configured to divert the respective optical signals to provide respective far field patterns over respective angles of the field of view that collectively define the non-uniform intensity distribution. 
     
     
         5 . The LIDAR apparatus of  claim 3 , wherein the at least one optical element comprises a plurality of lenslets, wherein respective shapes of the lenslets vary in one or more directions along a surface of the emitter array. 
     
     
         6 . The LIDAR apparatus of  claim 3 , wherein the at least one optical element comprises an optical diffuser. 
     
     
         7 . The LIDAR apparatus of  claim 2 , wherein the at least one optical element is configured to divert the respective optical signals output from the emitter elements positioned at respective regions of the emitter array to different portions of the field of view to alter a divergence of the output beam in a horizontal and/or vertical dimension. 
     
     
         8 . The LIDAR apparatus of  claim 1 , wherein the emitter elements are arranged with a non-uniform pitch between adjacent ones of the emitter elements. 
     
     
         9 . The LIDAR apparatus of  claim 8 , wherein a spacing between immediately adjacent ones of the emitter elements is about 500 micrometers or less. 
     
     
         10 . The LIDAR apparatus of  claim 1 , wherein the emitter elements comprise vertical cavity surface emitting lasers (VCSELs). 
     
     
         11 . A method of fabricating a light detection and ranging (LIDAR) emitter array, the method comprising:
 forming an emitter array comprising emitter elements that are configured to output respective optical signals to illuminate a field of view, wherein respective subsets of the emitter elements are electrically connected to one other anode-to-cathode on a surface of a non-native substrate; and   providing at least one optical element that is configured to divert the respective optical signals output from the emitter elements positioned at respective regions of the emitter array to different portions of the field of view.   
     
     
         12 . The method of  claim 11 , wherein the respective optical signals define an output beam having a non-uniform intensity distribution over the field of view. 
     
     
         13 . The method of  claim 12 , wherein the at least one optical element comprises respective regions having different optical characteristics. 
     
     
         14 . The method of  claim 13 , wherein the respective regions of the at least one optical element are configured to divert the respective optical signals to provide respective far field patterns over respective angles of the field of view that collectively define the non-uniform intensity distribution. 
     
     
         15 . The method of  claim 13 , wherein the at least one optical element comprises:
 a plurality of lenslets, wherein respective shapes of the lenslets vary in one or more directions along a surface of the emitter array; or   an optical diffuser.   
     
     
         16 . The method of  claim 12 , wherein the at least one optical element is configured to divert the respective optical signals output from the emitter elements positioned at respective regions of the emitter array to different portions of the field of view to alter a divergence of the output beam in a horizontal and/or vertical dimension. 
     
     
         17 . The method of  claim 1 , wherein the emitter elements are arranged with a non-uniform pitch between adjacent ones of the emitter elements. 
     
     
         18 . A light detection and ranging (LIDAR) apparatus, comprising:
 an emitter array comprising emitter elements that are configured to output respective optical signals to illuminate a field of view, wherein respective subsets of the emitter elements are electrically connected to one other anode-to-cathode with a non-uniform pitch on a surface of a non-native substrate,   wherein the respective optical signals define an output beam having a non-uniform intensity distribution over the field of view.   
     
     
         19 . The LIDAR apparatus of  claim 18 , wherein a spacing between immediately adjacent ones of the emitter elements is about 500 micrometers or less. 
     
     
         20 . The LIDAR apparatus of  claim 18 , wherein the emitter elements comprise vertical cavity surface emitting lasers (VCSELs).