Stress-analysis method for optical waveguides composed of elastically anisotropic materials and its application to strain-induced optical waveguides

Abstract

In this paper we propose a new stress analysis method that can evaluate the residual thermal stress distribution in an optical waveguide with an elastically arbitrary anisotropy. We analyze the optical waveguide by taking into account the refractive index change obtained from stress analysis. A rigorous evaluation of the propagation characteristics in a strain‐induced optical waveguide is now possible. Since the finite‐element method is used for both the stress analysis and the optical waveguide analysis, the complex refractive index change obtained from stress analysis can be faithfully reflected in the optical waveguide analysis. Strain‐induced optical waveguides with a SiO2/GaAs structure and a SiO2/LiNbO3 structure are chosen. The stress and strain in the waveguide and the change of the refractive index profile are obtained numerically and their effects on the transmission characteristics of the optical wave are studied. To the best of our knowledge, this is the first time that an optical waveguide analysis has been carried out from stress analysis taking into account an anisotropy. © 1998 Scripta Technica, Electron Comm Jpn Pt 2, 81(5): 16–23, 1998

Mechanical–Structural Investigation of Ion-Exchanged Lithium Silicate Glass using Micro-Raman Spectroscopy

“…Uniquely, IE produces high stresses, several hundreds of MPa, ,− over a shallow case depth, ≤100 μm, which allows objects that cannot undergo thermal tempering, e.g., irregularly shaped and thin glass objects, to be strengthened nevertheless. Due to the compositional gradient, birefringence can be used to produce waveguides and the resulting changes in refractive index have been measured optically; nonetheless, the resulting stress profile is important as different stress states can affect the refractive index further. , …”

“…Due to the compositional gradient, birefringence can be used to produce waveguides and the resulting changes in refractive index have been measured optically; 3 nonetheless, the resulting stress profile is important as different stress states can affect the refractive index further. 7,8 The IE process is performed by placing the target object in a molten salt bath, e.g., KNO 3 , and the exchange is driven by ionconcentration differences between the inside of the glass and the salt bath. When performed below the glass transition temperature, T g , IE induces compressive stress on the glass network due to a larger ion filling a cavity recently vacated by a smaller ion while preventing significant relaxation or accommodation of the larger invading ion.…”