You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither SPIE nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the SPIE website.
1 May 2005Simple approach to calculate the refractive index profile of ion-exchanged waveguides
In graded-index glass waveguides a key factor for the design of components and devices is usually the accurate determination of the refractive index profile as a function of depth. The problem of reconstructing the index profile using the measured effective refractive indices has been faced by several authors. Here we suggest a new expression, linear combination of two analytical functions, which is able to provide a good approximation of the solution of the differential equation that rules the thermal diffusion process. The use of this equation, in connection with the general approach of inverting the Wentzel-Kramer-Bruilloin (WKB) eigenvalue equation, leads to a simple, fast, and accurate computation of the refractive index profile obtained by ion exchange. The application of the method to various Ag-exchanged waveguides in different glass matrices, with better accuracy than most of the usual procedures, has been demonstrated.