Conditions for bringing the ordinary and extraordinary rays into coincidence in a plane-parallel plate fabricated from an optical uniaxial crystal

摘要

This paper shows that there are directions in which the ordinary and extraordinary rays coincide in a plane-parallel plate fabricated from an optical uniaxial crystal. Such directions of coincidence are important in creating optical phase plates or light filters with oblique incidence of rays of small cross section onto a plate when holographic gratings or nonlinear-susceptibility gratings are being recorded.