Reflection ellipsometry of uniaxial crystals

Abstract

A method is proposed to determine the optical constants of uniaxial crystals by ellipsometry. The same scheme works for absorbing and nonabsorbing crystals. The quantities measured are ratios of the four reflection amplitudes rss,rsp,rps, and rpp, and angles. The common zeros of rsp and rps determine the symmetry direction (optic axis in the plane of incidence) at which rpp/rss is measured to obtain one equation linking the ordinary and extraordinary dielectric constants ∊o and ∊e, and the inclination χ of the optic axis to the normal to the reflecting plane. Measurement of rpp/rss at right angles to the symmetry direction, and of rsp/rps away from the symmetry direction gives two more equations for the unknowns. The method can be used on microscopic crystal faces.