High power handling polarization switches

Abstract

Liquid crystal devices are described that maintain performance of polarization/amplitude modulation under high irradiance conditions. Configurations that isolate polarizing elements under high thermal load are discussed which allow other elements, such as glass, which may be sensitive to stress birefringence to remain near optimum thermal conditions.

1 - 22 . (canceled) 
     
     
         23 . A polarization switch, comprising:
 a first assembly operable to receive light, comprising:
 a first end cap; 
 a first polarizer located to receive light from the first end cap; 
 a second end cap located to receive light from the first polarizer; 
   a second assembly located to receive light from the first assembly, comprising:
 a third end cap; 
 a first cell located to receive light from the third end cap; 
 a second cell located to receive light from the first cell; 
 a fourth end cap located to receive light from the second cell; 
   wherein an air gap separates the first assembly from the second assembly.   
     
     
         24 . The polarization switch of  claim 23 , wherein the first end cap is borofloat glass. 
     
     
         25 . The polarization switch of  claim 24 , wherein the first end cap comprises an anti-reflective coating. 
     
     
         26 . The polarization switch of  claim 23 , wherein the first polarizer is a dye polarizer. 
     
     
         27 . The polarization switch of  claim 23 , wherein the second assembly further comprises a second polarizer located to receive light from the third end cap, and wherein the first cell is further located to receive light from the second polarizer. 
     
     
         28 . The polarization switch of  claim 27 , wherein the second polarizer is an iodine polarizer. 
     
     
         29 . The polarization switch of  claim 23 , wherein the first cell and the second cell are liquid crystal cells. 
     
     
         30 . The polarization switch of  claim 23 , wherein the thickness of the first, second, third and fourth end caps are in the approximate range of 3-12 mm. 
     
     
         31 . The polarization switch of  claim 23 , wherein the second end cap is synthetic fused silica. 
     
     
         32 . The polarization switch of  claim 23 , wherein the second assembly further comprises a first compensator located to receive light from the first cell, a second compensator located to receive light from the first compensator, and a third compensator located to receive light from the second cell, wherein the second cell is further located to receive light from the second compensator, and wherein the fourth end cap is further located to receive light from the third compensator. 
     
     
         33 . The polarization switch of  claim 32 , wherein the first, second, and third compensators are -C compensators. 
     
     
         34 . The polarization switch of  claim 23 , wherein the air gap is in the approximate range of 0.5-10 mm.