Simple polarimetric approach to direct measurement of the near-surface refractive index in graded-index films.
In the standard M-line method for the characterization of graded-index film, 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.
Pereira
Marcelo B
MB
Instituto de Física, Universidade Federal do Rio Grande do Sul, 91501-970 Porto Alegre, Rio Grande do Sul, Brazil.
Horowitz
Flavio
F