OPTIMAL-DESIGN OF POLARIZING BEAM-SPLITTERS WITH A BIREFRINGENT SUBSTRATE

We present an optimal approach for designing polarizing beam splitters made of a sheet of birefringent material. The polarizing beam splitte r is in the form of a transmission diffraction grating with a surface- relief structure of periodic sawtooth shape. We describe the necessary conditions for optimal design and derive the relevant equations for d etermining the structural parameters of the gratings. We demonstrate h ow to choose these parameters for a given substrate material to obtain the best result in the designed polarizing beam splitters. The influe nce of small variations in the parameters on grating performance is al so investigated. It is shown that the performance of gratings is quite sensitive to small changes in the structural parameters. (C) 1997 Opt ical Society of America.