Analytical solutions to estimate the stress induced polarization shift and the temperature sensitivity of optical waveguides

Polarization shift and temperature sensitivity are important issues in optical waveguides. Applying stresses is a promising method to control these optical parameters. In this article, analytical solutions are obtained to estimate the stress effects on these optical parameters. Because the refractive index variation induced by the stresses is very small, the linear approximation is used to obtain the closed-form solutions to estimate the stress induced effective index change in a slab waveguide. The solutions are, then, extended to estimate the stress induced effective index change, polarization shift, and the temperature sensitivity of a channel waveguide by use of effective index method. As an example, the optical parameters controlled by the thermal stresses, which are induced by attaching an Al plate on the bottom of the substrate, are analyzed. The results show that the polarization shift and the temperature sensitivity of the central wavelength can be tuned in a large range by varying the Al plate thickness and the curing temperature. The effects can be modified by changing the shape of the Al plate. (C) 2004 American Institute of Physics.