OPTIMIZATION OF A RHOMB-TYPE QUARTER-WAVE PHASE RETARDER

A previously reported two-reflection, undeviating-beam total internal reflection (TIR) quarter-wave phase retarder is optimized. The specifi cations and characteristics of the device are sensitive to the refract ive index n of the rhomb material. In particular, the size of the rhom b can he reduced by a factor of 11 for the same aperture size if a gla ss with n = 1.70 is used instead of one with n = 1.53, Optimal conditi ons are in the refractive-index interval n = 1.68-1.71. Coated rhombs of this type are mentioned.