THEORY OF OBLIQUE-INCIDENCE PHASE RETARDERS

Phenomenological and mathematical analyses of oblique incidence in tot al-internal-reflection phase retarders and the procedure for construct ing extremely achromatic quarter-wave retarders are presented. It is s hown that the retardance can assume the same value twice at two defini te spectral lines. As an example, a quarter-wave phase retarder is des cribed that introduces a retardance of exactly 90 degrees at two He-Ne laser Lines of 632.8 and 1150 nm with a maximum deviation of 0.007 de grees for other wavelengths between these two Lines. This application is advantageous in conjunction with two-line and multiline lasers wher e the radiation is usually pumped in a state of circular polarization. (C) 1997 Optical Society of America.