Ultraviolet Polarization Beam Splitter with Minimum Apodization

Abstract

A beamsplitter includes a first fluoride prism and a second fluoride prism. A coating interface is between the first and second fluoride prisms, wherein an overall R(s)*T(p) function of the beamsplitter varies no more than ±2.74% in the range of 40-50 degrees of incidence.

1 . A beamsplitter comprising:
 a first fluoride prism;   a second fluoride prism;   a coating interface between the first and second fluoride prisms,   wherein a (R(s) function of the beamsplitter compensates for variations of a T(p) function of the beamsplitter such that variations of an apodization function of the beamsplitter is smaller than the variation of the T(p) function; and   wherein the coating interface includes alternating layers of first and second fluoride materials, the first fluoride material has a greater refractive index than the second fluoride material.   
     
     
         2 . The beamsplitter of  claim 1 , wherein the coating interface includes alternating layers of MgF 2  and LaF 3 . 
     
     
         3 . The beamsplitter of  claim 1 , wherein the coating interface includes alternating layers of NdF 3  and AlF 3 . 
     
     
         4 . The beamsplitter of  claim 1 , wherein the first and second prisms include CaF 2 . 
     
     
         5 . The beamsplitter of  claim 1 , wherein the overall R(s)*T(p) function of the beamsplitter varies no more than ±2.74% with reference to an average between the maximum value and the minimum value of the apodization function in the range of 35-55 degrees of incidence. 
     
     
         6 . The beamsplitter of  claim 1 , wherein the beamsplitter operates at about 157.6 nm. 
     
     
         7 . The beamsplitter of  claim 1 , wherein the beamsplitter operates at about 193 nm. 
     
     
         8 . A beamsplitter comprising:
 a first prism;   a second prism;   a coating interface between the first and second prisms,   wherein the first and second prisms include fused silica;   wherein a R(s) function of the beamsplitter compensates for variations of a T(p) function of the beamsplitter such that variations of an apodization function of the beamsplitter is smaller than the variation of the T(p) function; and   wherein the coating interface includes alternating layers of first and second fluoride materials, the first fluoride material has a greater refractive index than the second fluoride material.   
     
     
         9 . The beamsplitter of  claim 8 , wherein the coating interface includes alternating layers of MgF 2  and LaF 3 . 
     
     
         10 . The beamsplitter of  claim 8 , wherein the coating interface includes alternating layers of NdF 3  and AlF 3 . 
     
     
         11 . The beamsplitter of  claim 8 , wherein the overall R(s)*T(p) function of the beamsplitter varies no more than ±2.74% with reference to an average between the maximum value and the minimum value of the apodization function in the range of 35-55 degrees of incidence. 
     
     
         12 . The beamsplitter of  claim 8 , wherein the beamsplitter operates at about 157.6 nm. 
     
     
         13 . The beamsplitter of  claim 8 , wherein the beamsplitter operates at about 193 nm.