Loss anomalies in multilayer planar waveguides

Abstract

An apparatus based on guided waves and photothermal techniques permits to measure attenuation coefficients in multilayer waveguides produced by lAD and Ion Plating. Zero-order modes are used to obtain accurate values of extinction coefficients of T102 and Ta205 thin-film materials at wavelength 514.5 nm . On the other hand, higher-order modes reveal strong loss anomalies that are analyzed via electromagnetic theories ofscattering and absorption, both including surface and bulk effects.

Ellipsometry of light scattering from multilayer coatings

“…6 • The bulk correlation can be described in the same way, even though we have poor knowledge of how the bulk inhomogeneity can be reproduced from one bulk to another or brought to each bulk by materials. 13,17…”

Characterization of optical coatings by photothermal deflection

“…In our laboratory we also use PD for measuring the attenuation during guided propagation. 23 Simultaneous measurements of absorption and attenuation allow us to reach an accurate balance of energy losses. 22,23 Three general remarks can be made concerning the advantages and disadvantages of the different configurations.…”

“…23 Simultaneous measurements of absorption and attenuation allow us to reach an accurate balance of energy losses. 22,23 Three general remarks can be made concerning the advantages and disadvantages of the different configurations. First, if we consider the number of thermal or physical parameters of the film involved in PD, we find four parameters for the mirage effect: 1 C 1 , the heat capacity per unit volume; K 1 , the thermal conductivity; R FS , the thermal resistance at the filmsubstrate interface; and e, the thickness of the film.…”