Investigation of Thin Film Waveguides Using Leaky Modes for Laser Applications

Leaky modes have been observed and investigated. A simple method is used to evaluate refractive index and thickness by solving the so-called mode equation. Application and tests of the assessments are made using a thin film of SiO x N y elaborated by the PECVD technique. From the measured TE and TM mode spectra, it is found that the films are isotropic with good confinement of the light wave. Results are in good agreement with those reported by many authors for such kind of materials.