Measurement of the refractive-index variations with temperature of hybrid sol–gel glasses

• Published in: Thin solid films 2002-12, Vol.422 (1), p.161-165
• Main Authors: Moujoud, A, Saddiki, Z, Touam, T, Najafi, S.I
• Format: Article
• Language: English
• Subjects: Birefringence; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Optical properties of specific thin films, surfaces, and low-dimensional structures; Physics; Refractive index; Sol–gel
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/S0040-6090(02)00627-2

We report the measurement of variation in refractive index vs. temperature for organic–inorganic slab waveguides. The following parameters have been obtained: refractive index n; thermo-optic constant d n/d T; and linear thermal expansion coefficient. The refractive index has been measured between approximately 10 and 80 °C. For both polarization TE (Transverse Electric) and TM (Transverse Magnetic), the slopes (d n/d T) are linear over the temperature range with a correlation coefficient r≥0.997 at a wavelength of 632.8 nm. Using the prism coupling method we verified that the refractive index variations follow the Lorentz–Lorenz law. A zero-birefringence is obtained. The thermo-optic coefficient for different slab waveguides was found to be almost constant and not exceeding 10 −4/°C.