Correction of off-axis aberrations with a birefringent lens

Abstract

The imaging characteristic of a uniaxial birefringent crystal lens sandwiched between two linear polarizers is studied. The optic axis of the birefringent crystal is perpendicular to the lens axis. The combination behaves like an isotropic lens with a variable complex spatial mask on its pupil plane1-2. The mask function depends on the birefringent lens parameters along with the orientation of the transmission axes of the two polarizers. Obviously the virtual mask may be modified according to the specific requirement, either by rotating any of the two polarizers or by changing the lens parameters.