Open AccessAssessment of wavelength dependent complex refractive index of strongly light absorbing liquids
Author(s) -
Jukka Räty,
Pertti Pääkkönen,
Kai–Erik Peiponen
Publication year - 2012
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.002835
Subject(s) - transmittance , optics , refractive index , materials science , fresnel equations , reflectometry , attenuation coefficient , wavelength , dispersion (optics) , optoelectronics , physics , time domain , computer science , computer vision
A practical measurement procedure for the determination of the complex refractive index of strongly absorbing liquids within a finite spectral range was developed. The method is based on separate measurements of reflectance and transmittance of the liquid sample, a property of dispersion and absorption, and exploitation of Fresnel's theory. The advantage of the method is that the knowledge of the layer thickness of the light absorbing medium, which is required typically in transmittance measurements, is not needed. In addition, both measurements, the transmittance and the reflectance, were accomplished with one spectrophotometer using a home-built reflectometer and without any sample dilution. The method is validated by numerical simulation using the Lorentz model for permittivity of an insulator, and also by experimental data obtained from three strongly absorbing offset inks, namely magenta, yellow and cyan.