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 $r_{\mathit{ss}},$ $r_{\mathit{sp}},$ $r_{\mathit{ps}},$ and $r_{\mathit{pp}},$ and angles. The common zeros of $r_{\mathit{sp}}$ and $r_{\mathit{ps}}$ determine the symmetry direction (optic axis in the plane of incidence) at which $r_{\mathit{pp}}/r_{\mathit{ss}}$ 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 $r_{\mathit{pp}}/r_{\mathit{ss}}$ at right angles to the symmetry direction, and of $r_{\mathit{sp}}/r_{\mathit{ps}}$ away from the symmetry direction gives two more equations for the unknowns. The method can be used on microscopic crystal faces.

© 1997 Optical Society of America