The continuous wavelet transform (CWT) using the Gabor wavelet was applied to analyze the transmittance signal. Transmittance spectra of a mica film and 4-cyano 4'-pentyl biphenyl liquid crystal were acquired in the visible spectral region by using a monochromator, and the dispersion curves of the refractive index and the birefringence were deduced. The experimental data were fitted to the Cauchy's formula, and the dispersion parameters were extracted. The results obtained by the CWT approach were compared with the published values. (C) 2003 Elsevier B.V. All rights reserved.