Semiconductor lasers and processes for the planarization of semiconductor lasers

Abstract

A laser structure may include a substrate, an active region arranged on the substrate, and a waveguide arranged on the active region. The waveguide may include a first surface and a second surface that join to form a first angle relative to the active region. A material may be deposited on the first surface and the second surface of the waveguide.

1 . A laser structure, comprising:
 a substrate;   an active region arranged on the substrate;   a waveguide arranged on the active region, the waveguide including a first surface and a second surface that join to form a first angle relative to the active region; and   a material deposited on the first surface and the second surface of the waveguide.   
     
     
         2 . The laser structure of  claim 1 , wherein the first angle is less than ninety degrees. 
     
     
         3 . The laser structure of  claim 1 , wherein the waveguide further includes a third surface and a fourth surface that join to form a second angle relative to the active region, and the material is deposited on the third surface and the fourth surface. 
     
     
         4 . The laser structure of  claim 3 , wherein the second angle is less than ninety degrees. 
     
     
         5 . The laser structure of  claim 1 , wherein the material is one of MgO, MgF 2 , SiO 2 , or Si 3 N 4 . 
     
     
         6 . The laser structure of  claim 1 , wherein the material has a dielectric constant below  10  in a frequency range up to 50 GHz. 
     
     
         7 . The laser structure of  claim 1 , wherein the material is non-conducting. 
     
     
         8 . The laser structure of  claim 1 , wherein the waveguide includes a fifth surface arranged between the first surface and the third surface, and the laser structure further comprises:
 a first contact arranged on the fifth surface; and   a second contact arranged on the substrate,   wherein the first contact is configured to bias the laser structure by delivering electrical current to the laser structure.   
     
     
         9 . The laser structure of  claim 1 , further comprising at least one facet. 
     
     
         10 . The laser structure of  claim 9 , wherein the at least one facet is formed in the active region. 
     
     
         11 . A laser structure, comprising:
 a substrate;   an active region arranged on the substrate;   a waveguide arranged on the active region, the waveguide including a first ridge and a second ridge, wherein the first ridge forms a first air gap and the second ridge forms a second air gap; and   a metal layer arranged as a bridge over the first and second air gaps.   
     
     
         12 . The laser structure of  claim 11 , wherein the first ridge forms a first angle of less than ninety degrees relative to the active region and the second ridge forms a second angle of less than ninety degrees relative to the active region. 
     
     
         13 . The laser structure of  claim 11 , wherein a first contact is arranged on a surface of the waveguide and the first contact is configured to bias the laser structure by delivering electrical current to the laser structure. 
     
     
         14 . The laser structure of  claim 11 , further comprising at least one facet. 
     
     
         15 . The laser structure of  claim 14 , wherein the at least one facet is formed in the active region. 
     
     
         16 . A method of fabricating a laser structure, comprising:
 arranging an active region on a substrate;   arranging a waveguide on the active region, the waveguide including a first ridge and a second ridge;   depositing a polymer on the waveguide such that the polymer coats underneath the first ridge and second ridge;   depositing at least one layer of resist on the polymer;   depositing a metal layer on the at least one layer of resist; and   removing the deposited polymer and the deposited at least one layer of resist.   
     
     
         17 . The method of  claim 16 , wherein the first ridge forms a first angle of less than ninety degrees relative to the active region and the second ridge forms a second angle of less than ninety degrees relative to the active region. 
     
     
         18 . The method of  claim 16 , further comprising arranging a first contact on a surface of the waveguide, wherein the first contact is configured to bias the laser structure by delivering electrical current to the laser structure. 
     
     
         19 . The method of  claim 16 , further comprising forming at least one facet in the active region. 
     
     
         20 . The method of  claim 19 , wherein the at least one facet is formed by etching. 
     
     
         21 . A fixture for electron beam evaporation, the fixture comprising:
 a wafer plate configured to support a laser structure; and   an integrated heater configured to emit heat at an evaporation temperature,   wherein the heat emitted by the integrated heater is adjustable and an angle of the fixture is adjustable.   
     
     
         22 . The fixture of  claim 21 , wherein the wafer plate is further configured to orient the laser structure relative to an evaporant. 
     
     
         23 . The fixture of  claim 21 , wherein the orientation of the laser structure subjects at least one ridge of the laser structure to the evaporant. 
     
     
         24 . The fixture of  claim 21 , wherein the orientation of the laser structure is varied based on an angle of at least one ridge of the laser structure.