Jan Mistrik

Optical Properties of Electronic Materials: Fundamentals and Characterization

Light interacts with materials in a variety of ways; this chapter focuses on refraction and absorption. Refraction is characterized by a material’s refractive index. We discuss some of the most useful models for the frequency dependence of the refractive index, such as those due to Cauchy, Sellmeier, Gladstone–Dale, and Wemple–DiDominico. Examples are given of the applicability of the models to actual materials. We present various mechanisms of light absorption, including absorption by free carriers, phonons, excitons and impurities. Special attention is paid to fundamental and excitonic absorption in disordered semiconductors and to absorption by rare earth, trivalent ions due to their importance in modern photonics. We also discuss the effect of an external electric field on absorption, and the Faraday effect. Practical techniques for determining the optical parameters of thin films are outlined. Finally, we present a short technical classification of optical glasses and materials.

Rigorous coupled wave analysis for deep structures with internal field distribution

The rigorous coupled wave analysis is demonstrated by employing a recursive propagation algorithm based on an Airy-like internal reflection series, modified for a general cross-sectional distribution of permittivity. The method is capable of determining the electromagnetic field value at any point of the structure of any depth. Examples of simulation are presented on a nearly sinusoidal relief grating fabricated on the top of a Ni substrate.

Spectroscopic ellipsometry characterization of sine-like surface relief Ni gratings

Spectroscopic ellipsometry was employed for determination of structural parameters of holographic Ni grating: its period and profile depth. Native oxide overlayer was also taken into account. Moreover slight deviation of sine-like profile was considered and analyzed. Obtained results were compared with conventional complementary methods as scanning electron microscopy, atomic force microscopy and optical microscopy. Advantages and disadvantages of all above mentioned approaches were presented.