Improved near-field method for refractive index measurement of optical waveguides
- 1 February 1996
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Photonics Technology Letters
- Vol. 8 (2), 254-256
- https://doi.org/10.1109/68.484258
Abstract
Refractive index profiles of waveguides are deduced from near-field intensity distributions of guided modes. To improve the accuracy of refractive index profiles, some measurements are taken with the center peak of the mode intensity profile blocked, allowing the increase of the optical power at the waveguide boundaries with a corresponding increase in the signal-to-noise ratio. Additional improvements reported here are related to the subsequent signal processing, which is performed mainly in the spatial frequency domain. Smooth and reliable profiles of channel waveguides are obtained, the method being very general and not presuming the functional dependence of n(x, y).Keywords
This publication has 4 references indexed in Scilit:
- Error analysis for refractive-index profile determination from near-field measurementsJournal of Lightwave Technology, 1990
- Far-field power-distribution measurement in axially symmetrical and nonsymmetrical fibers using a variable-width slitOptics Letters, 1990
- Index profiling of three-dimensional optical waveguides by the propagation-mode near-field methodJournal of Lightwave Technology, 1986
- Index distribution of optical waveguides from their mode profileJournal of Lightwave Technology, 1983