Optical waveguides and methods of making the same

Abstract

An optical waveguide includes a silicon wafer having two opposed sides. A first notch is defined in each of the two opposed sides such that the silicon wafer includes a head portion and a first stem portion.

What is claimed is: 
     
         1 . An optical waveguide, comprising:
 a silicon wafer having two opposed sides;   a first notch defined in each of the two opposed sides such that the silicon wafer includes a head portion and a first stem portion.   
     
     
         2 . The optical waveguide as defined in  claim 1 , further comprising a second notch defined in each of the two opposed sides a spaced distance from the respective first notches. 
     
     
         3 . The optical waveguide as defined in  claim 2  wherein each first notch includes a rounded edge and a substantially straight edge, and wherein each second notch includes a rounded edge. 
     
     
         4 . The optical waveguide as defined in  claim 2  wherein the silicon wafer further includes a second stem portion defined by the second notches. 
     
     
         5 . The optical waveguide as defined in  claim 4  wherein at least one of the first stem portion or the second stem portion is partially or fully oxidized. 
     
     
         6 . The optical waveguide as defined in  claim 4 , further comprising:
 a top portion of the silicon wafer adjacent the second stem portion; and   an electrical contact operatively connected to the top portion.   
     
     
         7 . The optical waveguide as defined in  claim 4 , further comprising:
 a doped top portion of the silicon wafer adjacent the second stem portion;   a first electrical contact operatively connected to the doped top portion;   a doped bottom portion of the silicon wafer adjacent the first stem portion; and   a second electrical contact operatively connected to the doped bottom portion.   
     
     
         8 . The optical waveguide as defined in  claim 7  wherein the top portion is doped to have one of p-type conductivity or n-type conductivity and wherein the bottom portion is doped to have an other of n-type conductivity or p-type conductivity. 
     
     
         9 . The optical waveguide as defined in  claim 1  wherein a transverse electric mode of the optical waveguide is substantially confined in the head portion. 
     
     
         10 . The optical waveguide as defined in  claim 1  wherein the first stem portion is partially or fully oxidized. 
     
     
         11 . A method of making an optical waveguide, comprising:
 sequentially anisotropically and isotropically etching two opposed sides of a silicon wafer, thereby forming a first notch in each of the two opposed sides and defining a head portion and a first stem portion of the silicon wafer.   
     
     
         12 . The method as defined in  claim 11 , further comprising forming a second notch in each of the two opposed sides a spaced distance from the respective first notches during the sequential isotropic and anisotropic etching processes. 
     
     
         13 . The method as defined in  claim 12  wherein the second notches define a second stem portion of the silicon wafer, and wherein the method further comprises partially or fully oxidizing at least one of the first stem portion or the second stem portion. 
     
     
         14 . The method as defined in  claim 13 , further comprising:
 defining a top portion of the silicon wafer adjacent the second stem portion; and   operatively connecting an electrical contact to the top portion.   
     
     
         15 . The method as defined in  claim 14 , further comprising:
 doping the top portion;   doping a bottom portion of the silicon wafer that is adjacent the first stem portion; and   operatively connecting a second electrical contact to the doped bottom portion.