Rochon polarizer is one of the earliest designs ,which is made of two Birefringent material prisms cemented or optical contacted together .Both ordinary and extraordinary beams propagate collinearly down the optic axis in the first prism under the ordinary refractive index, Upon entering the second prism the ordinary beam, however ,now has a lower refractive index and is refracted at the interface. Any separation angle can be for designed for specific wavelength upon requirement.