Emitter array with shared via to an ohmic metal shared between adjacent emitters

Abstract

An emitter array may comprise a plurality of emitters that includes two adjacent emitters. The emitter array may comprise a plurality of emitters that includes two adjacent emitters. The ohmic metal layer may include a portion that is shared by, and located between, the two adjacent emitters. The emitter array may comprise a protective layer over the ohmic metal layer. The emitter array may comprise a via through the protective layer to the portion. The via is shared by, and located between, the two adjacent emitters.

What is claimed is: 
     
         1 . A space-conserving vertical cavity surface emitting laser (VCSEL) array, comprising:
 a plurality of VCSELs including two adjacent VCSELs;   a metallization layer; and   an ohmic metal layer associated with the plurality of VCSELs,
 wherein a portion of the ohmic metal layer is shared by the two adjacent VCSELs, 
 wherein a first radial distance from each of the two adjacent VCSELs to the portion of the ohmic metal layer is less than a second radial distance from each of the two adjacent VCSELs to a trench shared by the two adjacent VCSELs, and 
 wherein a difference between an optical aperture diameter of at least one of the two adjacent VCSELs and a pitch distance between the two adjacent VCSELs is reduced, relative to emitter arrays without the portion of the ohmic metal layer. 
   
     
     
         2 . The VCSEL array of  claim 1 , wherein the difference between the optical aperture diameter and the pitch distance is less than 9 microns. 
     
     
         3 . The VCSEL array of  claim 1 , wherein the optical aperture diameter is between 4 microns and 20 microns. 
     
     
         4 . The VCSEL array of  claim 1 , wherein the pitch distance is between 16 microns and 20 microns. 
     
     
         5 . The VCSEL array of  claim 1 , wherein a via to the portion of the ohmic metal layer is shared by the two adjacent VCSELs. 
     
     
         6 . The VCSEL array of  claim 5 , wherein the via electrically connects the metallization layer to the ohmic metal layer. 
     
     
         7 . The VCSEL array of  claim 1 , wherein the ohmic metal layer comprises a plurality of separate ohmic metal portions that surround at least one of the plurality of VCSELs. 
     
     
         8 . A high-density vertical cavity surface emitting laser (VCSEL) array, comprising:
 a plurality of VCSELs including two adjacent VCSELs;   a metallization layer; and   an ohmic metal layer associated with the plurality of VCSELs,
 wherein a portion of the ohmic metal layer is shared by the two adjacent VCSELs, 
 wherein a first radial distance from each of the two adjacent VCSELs to the portion of the ohmic metal layer is less than a second radial distance from each of the two adjacent VCSELs to a trench shared by the two adjacent VCSELs, and 
 wherein a ratio of an optical aperture diameter of one of the two adjacent VCSELs to a pitch distance between the two adjacent VCSELs enables the plurality of VCSELs to be arranged at a higher density than emitter arrays without the portion of the ohmic metal layer. 
   
     
     
         9 . The VCSEL array of  claim 8 , wherein the ratio of the optical aperture diameter and the pitch distance is greater than 11:20. 
     
     
         10 . The VCSEL array of  claim 8 , wherein the optical aperture diameter is between 4 microns and 20 microns. 
     
     
         11 . The VCSEL array of  claim 8 , wherein the pitch distance is between 16 microns and 20 microns. 
     
     
         12 . The VCSEL array of  claim 8 , wherein the ohmic metal layer comprises a plurality of separate ohmic metal portions that surround at least one of the plurality of VCSELs. 
     
     
         13 . The VCSEL array of  claim 8 , wherein a via to the portion of the ohmic metal layer is shared by the two adjacent VCSELs. 
     
     
         14 . The VCSEL array of  claim 13 , wherein the via electrically connects the metallization layer to the ohmic metal layer. 
     
     
         15 . A space-conserving emitter array, comprising:
 a plurality of emitters including two adjacent emitters;   a metallization layer; and   an ohmic metal layer associated with the plurality of emitters,
 wherein a portion of the ohmic metal layer is shared by the two adjacent emitters, 
 wherein a trench is shared by the two adjacent emitters, and 
 wherein a difference between an optical aperture diameter of at least one of the two adjacent emitters and a pitch distance between the two adjacent emitters is reduced, relative to emitter arrays without the portion of the ohmic metal layer. 
   
     
     
         16 . The emitter array of  claim 15 , wherein the difference between the optical aperture diameter and the pitch distance is less than 9 microns. 
     
     
         17 . The emitter array of  claim 15 , wherein the optical aperture diameter is between 4 microns and 20 microns. 
     
     
         18 . The emitter array of  claim 15 , wherein the pitch distance is between 16 microns and 20 microns. 
     
     
         19 . The emitter array of  claim 15 , wherein a via to the portion of the ohmic metal layer is shared by the two adjacent emitters. 
     
     
         20 . The emitter array of  claim 15 , wherein the ohmic metal layer comprises a plurality of separate ohmic metal portions that surround at least one of the plurality of emitters.