High brightness LED package

Abstract

Light sources are disclosed utilizing LED dies that have a light emitting surface. A patterned low refractive index layer that can support total internal reflection within the LED die is provided in optical contact with a first portion of the emitting surface. In optical contact with a second portion of the emitting surface is an input surface of an optical element. The refractive index of the low index layer is below both that of the optical element and the LED die. The optical element can have a variety of shapes and sizes.

1 . A light source, comprising: 
 an LED die having an emitting surface;    a patterned low index layer in optical contact with a first portion of the emitting surface, the patterned layer having a first refractive index; and    an optical element having an input surface in optical contact with a second portion of the emitting surface, the optical element having a second refractive index higher than the first refractive index.    
   
   
       2 . The light source of  claim 1 , wherein the patterned low index layer provides total internal reflection at the emitting surface of the LED for at least some light generated within the LED die.  
   
   
       3 . A light source, comprising: 
 an LED die having an emitting surface;    means for totally internally reflecting at least some of the light generated by the LED die back into the LED die, the reflecting means being in optical contact with a first portion of the emitting surface; and    an optical element having an input surface in optical contact with a second portion of the emitting surface different from the first portion.    
   
   
       4 . The light source of  claim 3 , wherein the reflecting means comprises a patterned low index layer in optical contact with the first portion of the emitting surface, the patterned layer having a first refractive index.  
   
   
       5 . The light source of either  claim 1  or  4 , wherein the patterned low index layer comprises a dielectric material in optical contact with the first portion of the emitting surface and having the first refractive index, and a normal incidence reflector covering the dielectric material.  
   
   
       6 . The light source of  claim 5 , wherein the normal incidence reflector comprises a metal coating.  
   
   
       7 . The light source of  claim 5 , wherein the normal incidence reflector comprises an interference reflector.  
   
   
       8 . The light source of either  claim 1  or  4 , wherein the patterned low index layer comprises air or vacuum.  
   
   
       9 . The light source of either  claim 1  or  4 , wherein the optical element has a shape that collimates light received by its input surface.  
   
   
       10 . The light source of  claim 9 , wherein the optical element includes a tapered side surface.  
   
   
       11 . The light source of  claim 9 , wherein the optical element has a curved output surface.  
   
   
       12 . The light source of either  claim 1  or  4 , wherein the optical element has an output surface larger than the input surface.  
   
   
       13 . The light source of  claim 12 , wherein the optical element comprises at least one reflective side surface between the input and output surfaces.  
   
   
       14 . The light source of either  claim 1  or  4 , wherein the optical element comprises a material selected from the group of sapphire, diamond, and silicon carbide.  
   
   
       15 . The light source of either  claim 1  or  4 , wherein the first and second portions are complementary.  
   
   
       16 . The light source of either  claim 1  or  4 , wherein the patterned low index layer defines at least one aperture.  
   
   
       17 . The light source of  claim 16 , wherein the patterned low index layer includes portions within the at least one aperture.  
   
   
       18 . The light source of either  claim 1  or  4 , wherein the optical element has a refractive index of at least about 1.8.