Birefringent filter with arbitrary orientation of the optic axis: an analysis of improved accuracy.

The transmission characteristics of a birefringent quartz filter inserted under Brewster's angle into a linear laser resonator is investigated theoretically and experimentally for arbitrary orientations of the optic axis. Exact expressions for filter curves of zero losses as functions of wavelength and orientation of the optic axis are given and confirmed by measurements. The Jones matrix of birefringent filter, which describes the propagation of plane waves through the filter with improved accuracy, is derived. Transmission curves are calculated, showing that the optimum selectivity strongly depends on the orientation of the optic axis. For a special filter the results are verified by measurements.