The Layer Characterization mode of OptiChar provides a choice of a model from the set of models of a homogeneous thin film. The set includes models the refractive index and extinction coefficient wavelength dependencies:

• Cauchy model (Normal dispersion)
• Sellmeier models
• Model-free refractive index and extinction coefficient
• Arbitrary Dispersion
• Exponential model for extinction coefficient (UV-VIS)
• Hartmann model

You can specify the limits for thin film parameters according to the a priori information about optical properties of the film.

Unique non-parametric models can be used in complicated characterization problems.

1. A. Tikhonravov, M. Trubetskov, T. Amotchkina, G. DeBell, V. Pervak, A. Sytchkova, M. Grilli, and D. Ristau, "Optical parameters of oxide films typically used in optical coating production," Appl. Opt. 50, C75-C85 (2011).
2. T. Amotchkina, M. Trubetskov, A. Tikhonravov, V. Janicki, J. Sancho-Parramon, O. Razskazovskaya, and V. Pervak, "Oscillations in spectral behavior of total losses (1 - R - T) in thin dielectric films," Opt. Express 20, 16129-16144 (2012).
3. T.V. Amotchkina, V. Janicki, J. Sancho-Parramon, A.V. Tikhonravov, M.K. Trubetskov, and H. Zorc. "General approach to reliable characterization of thin metal films." Appl. Opt. 50, 10, 1453-1464 (2011).
4. T.V. Amotchkina, M.K. Trubetskov, A. V. Tikhonravov, V. Janicki, J. Sancho-Parramon, and H. Zorc. "Comparison of two techniques for reliable characterization of thin metal-dielectric films." Appl. Opt. 50, 6189-6197 (2011).
5. T. V. Amotchkina, D. Ristau, M. Lappschies, M. Jupe, A. V. Tikhonravov, and M. K. Trubetskov, "Optical Properties of TiO₂ -SiO₂ Mixture Thin Films Produced by Ion-Beam Sputtering," in Optical Interference Coatings, OSA Technical Digest (CD) (Optical Society of America, 2007), paper TuA8.
6. S. Nevas, F. Manoocheri, E. Ikonen, A. V. Tikhonravov, M. A. Kokarev, M. K. Trubetskov, Optical metrology of thin films using high-accuracy spectrophotometric measurements with oblique angles of incidence, Proc. SPIE. 5250, Advances in Optical Thin Films 234 (2004).
7. A. V. Tikhonravov, M. K. Trubetskov, A. A. Tikhonravov, and A. Duparre', "Effects of interface roughness on the spectral properties of thin films and multilayers ," Appl. Opt. 42, 5140-5148 (2003).
8. A. V. Tikhonravov, M. K. Trubetskov, G. W. DeBell, On the accuracy of optical thin film parameter determination based on spectrophotometric data, Proc. SPIE. 5188, Advanced Characterization Techniques for Optics, Semiconductors, and Nanotechnologies 190 (2003).
9. A. V. Tikhonravov, M. K. Trubetskov, T. V. Amotchkina, A. A. Tikhonravov, D. Ristau, S. Günster, Reliable determination of wavelength dependence of thin film refractive index, Proc. SPIE. 5188, Advanced Characterization Techniques for Optics, Semiconductors, and Nanotechnologies 331 (2003).
10. A. V. Tikhonravov, M. K. Trubetskov, M. A. Kokarev, T. V. Amotchkina, A. Duparr, E. Quesnel, D. Ristau, and S. Gunster, "Effect of systematic errors in spectral photometric data on the accuracy of determination of optical parameters of dielectric thin films ," Appl. Opt. 41, 2555-2560 (2002).
11. D. Ristau, S. Gunster, S. Bosch, A. Duparre, E. Masetti, J. Ferre-Borrull, G. Kiriakidis, F. Peiro, E. Quesnel, and A. Tikhonravov, "Ultraviolet optical and microstructural properties of MgF2 and LaF3 coatings deposited by ion-beam sputtering and boat and electron-beam evaporation ," Appl. Opt. 41, 3196-3204 (2002).
12. A. Tikhonravov, M. K. Trubetskov, A. V. Krasilnikova, E. Masetti, A. Duparre, E. Quesnel, and D. Ristau, "Invesitigation of the surface micro-roughness of fluoride films by spectrometric ellipsometry," Thin Solid Films 397, 229-237 (2001).
13. A. V. Tikhonravov, M. K. Trubetskov, E. Masetti, A. V. Krasilnikova, I. V. Kochikov, Sensitivity of the ellipsometric angles psi and delta to the surface inhomogeneity, Proc. SPIE. 3738, Advances in Optical Interference Coatings 173 (1999).
14. A. V. Tikhonravov, M.K. Trubetskov, G. Clarke, B. T. Sullivan, J. A. Dobrowolski, Ellipsometric study of optical properties and small inhomogeneities of Nb₂O₅ films, Proc. SPIE. 3738, Advances in Optical Interference Coatings 183 (1999).
15. A. V. Tikhonravov, M. K. Trubetskov, and A. V. Krasilnikova, "Spectroscopic ellipsometry of slightly inhomogeneous nonabsorbing thin films with arbitrary refractive-index profiles: theoretical study ," Appl. Opt. 37, 5902-5911 (1998).
16. A. V. Tikhonravov, M. K. Trubetskov, B. T. Sullivan, and J. A. Dobrowolski, "Influence of small inhomogeneities on the spectral characteristics of single thin films ," Appl. Opt. 36, 7188-9198 (1997).
17.  A. V. Tikhonravov, M. K. Trubetskov, Program package for the ellipsometry of inhomogeneous layers, Proc. SPIE. 2046, Inhomogeneous and Quasi-Inhomogeneous Optical Coatings 167 (1993)