Unified analytical inversion of reflectometric and ellipsometric data of absorbing media

We present a unified two-step analytical inversion of reflectometric and el lipsometric data of absorbing media. Instead of a direct determination of t he optical constants n, kappa from reflectometric or ellipsometric measurem ents, we first calculate the real and the imaginary part eta, gamma of the normal component of the wave vector in the absorbing medium. New and simple analytical formulas are obtained for eta and gamma in terms of rho(s), rho (p) or tan psi, delta, respectively, where rho(s), rho(p) and tan psi, delt a are the measured reflectometric and ellipsometric parameters of the absor bing medium. The optical constants are then easily determined analytically again from eta , gamma We use the new formulas to compare the sensitivity w ith experimental errors due to the inversion of reflectometric and ellipsom etric data. (C) 2000 Optical Society of America OCIS codes: 240.0240, 160.4 760, 240.6490, 120.4530, 260.2130.