Three-stage birefringent filter tuning smoothly over the visible region: theoretical treatment and experimental design

The Jones transformation matrix, which describes the arbitrary incidence of polarized light on a thin uniaxial birefringent plate, is determined. With the optic axis presumed to lie in the plane of the plate, digital solutions to the resulting formulas are presented for several different quartz plates to depict the tuning characteristics of a birefringent plate functioning as a single-stage birefringent filter. A simplified model is used to generalize these results to describe a multistage birefringent filter. This theoretical study forms the basis for the design and construction of a three stage, quartz, birefringent filter to be used as the coarse tuning element in a visible cw dye laser. A relatively simple and straightforward procedure for the assembly of the three-stage filter is given. The performance of this newly constructed filter is found to be superior to currently available commercial models, tuning smoothly over the 4400-6600-A wavelength region.