In the standard M-line method for the characterization of graded-index films, an analytical curve is fitted to the waveguide mode measurements and extrapolated to provide the refractive index in the zero-depth limit. Here we review our polarimetric approach to a direct near-surface measurement, which complements the M-line method. Also, we present its new and more straightforward version, which is applicable to existing samples and does not require masking before ion exchange.
© 2003 Optical Society of America
Original Manuscript: August 6, 2002
Revised Manuscript: February 13, 2003
Published: June 1, 2003
Marcelo B. Pereira and Flavio Horowitz, "Simple polarimetric approach to direct measurement of the near-surface refractive index in graded-index films," Appl. Opt. 42, 3268-3270 (2003)