High thermal conductivity vertical cavity surface emitting laser (VCSEL)

Abstract

A light generating device such as a VCSEL includes a light generation layer, a top reflector, a bottom reflector, and a high thermal conductivity (HTC) layer between the light generation layer and the bottom reflector. The light generation layer is adapted to generate light having a first wavelength. Heat produced at the light generation layer is more efficiently dissipated due to the presence of the HTC layer. Alternatively, a light generating device such as a VCSEL includes a light generation layer, a top reflector, and a high thermal conductivity (HTC) bottom reflector. Heat produced at the light generation layer is more efficiently dissipated due to the fact that the bottom reflector is a HTC DBR reflector having lower thermal resistivity than a conventional DBR reflector.

1 . A light generating device comprising: 
 a light generation layer adapted to generate light having a known wavelength;    a top reflector above said light generation layer;    a bottom reflector below said light generation layer; and    at least one of a high thermal conductivity (HTC) layer between said light generation layer and said bottom reflector and a high thermal conductivity (HTC) layer between said light generation layer and said top reflector.    
     
     
         2 . The light generating device recited in  claim 1  wherein said top reflector is a distributed Bragg reflector (DBR).  
     
     
         3 . The light generating device recited in  claim 1  wherein said HTC layer is an integer multiple of one-half wavelength thick.  
     
     
         4 . The light generating device recited in  claim 1  wherein said HTC layer comprises an element selected from a group consisting of Aluminum Arsenide, Gallium Arsenide, and Indium phosphide.  
     
     
         5 . The light generating device recited in  claim 1  further comprising a first electrode connected to said top reflector and a second electrode connected to said bottom reflector.  
     
     
         6 . The light generating device recited in  claim 1  further comprising a contact layer adapted to provide electronic contact between an electrode and said light generation layer.  
     
     
         7 . The light generating device recited in  claim 6  further comprising an etch stop layer in connection with said contact layer.  
     
     
         8 . A light generating device comprising: 
 a light generation layer adapted to generate light having a known wavelength;    a top reflector above said light generation layer; and    a high thermal conductivity (HTC) bottom reflector below said light generation layer.    
     
     
         9 . The light generating device recited in  claim 8  wherein said HTC bottom reflector comprises at least one distributed Bragg reflector (DBR) layer pair.  
     
     
         10 . The light generating device recited in  claim 9  wherein the distributed Bragg reflector (DBR) pairs comprise high thermal conductivity material.  
     
     
         11 . The light generating device recited in  claim 9  wherein each of the HTC DBR layer pair comprises a first layer having a first thermal conductivity and having a first thickness that is a quarter of the known wavelength, and a second layer having a second thermal conductivity and having a second thickness that is an odd multiple of quarter of the known wavelength.  
     
     
         12 . The light generating device recited in  claim 11  wherein the second thermal conductivity is higher than the first thermal conductivity.  
     
     
         13 . The light generating device recited in  claim 11  wherein the second layer comprises Aluminum Arsenide.  
     
     
         14 . The light generating device recited in  claim 9  wherein each of the HTC layer pair comprises a first layer having a first thermal conductivity and having a first thickness that is a quarter of the known wavelength, and a second layer having a second thermal conductivity and having a second thickness that is an odd multiple of quarter of the known wavelength.  
     
     
         15 . The light generating device recited in  claim 14  wherein the second thermal conductivity is higher than the first thermal conductivity.  
     
     
         16 . The light generating device recited in  claim 14  wherein the second layer comprises Aluminum Arsenide.  
     
     
         17 . The light generating device recited in  claim 9  wherein said HTC bottom reflector comprises non-uniform HTC layer pairs.  
     
     
         18 . The light generating device recited in  claim 17  wherein said HTC bottom reflector comprises a first HTC layer pair, the first HTC layer pair including a first layer having a first thermal conductivity and having a first thickness that is a quarter of the known wavelength, and a second layer having a second thermal conductivity and having a second thickness that is an odd multiple of quarter of the known wavelength.  
     
     
         19 . The light generating device recited in  claim 18  wherein said HTC bottom reflector comprises a second HTC layer pair, the second HTC layer pair including a third layer having the first thermal conductivity and having the first thickness, and a fourth layer having the second thermal conductivity and having a third thickness that is an odd multiple of quarter of the known wavelength, the third thickness different than the second thickness.  
     
     
         20 . The light generating device recited in  claim 19  wherein said HTC bottom reflector comprises a third HTC layer pair, the third HTC layer pair including a fifth layer having the first thermal conductivity and having the first thickness, and a sixth layer having the second thermal conductivity and having a fourth thickness that is an odd multiple of quarter of the known wavelength, the fourth thickness different from the third or the second thicknesses.