Abstract

Using a multifunction spectrophotometer, the refractive index of a pigment can be estimated by measuring the backscattering of light from the pigment in immersion liquids having slightly different refractive indices. A simple theoretical Gaussian function model related to the optical path distribution is introduced that makes it possible to describe quantitatively the backscattering signal from transparent pigments using a set of only a few immersion liquids. With the aid of the data fitting by a Gaussian function, the measurement time of the refractive index of the pigment can be reduced. The backscattering measurement technique is suggested to be useful in industrial measurement environments of pigments.

Measurement of refractive index of isotropic particles by incorporating a multifunction spectrophotometer and immersion liquid method

Ilpo Niskanen, Jukka Räty, and Kai-Erik Peiponen
Appl. Opt. 46(22) 5404-5407 (2007)

Optical sensing of concentration and refractive index of pigments in a suspension

Ilpo Niskanen, Jukka Räty, and Kai-Erik Peiponen
Appl. Opt. 49(17) 3428-3433 (2010)

Complex refractive index of turbid liquids

Ilpo Niskanen, Jukka Räty, and Kai-Erik Peiponen
Opt. Lett. 32(7) 862-864 (2007)

Assessment of wavelength dependent complex refractive index of strongly light absorbing liquids

Jukka Räty, Pertti Pääkkönen, and Kai-Erik Peiponen
Opt. Express 20(3) 2835-2843 (2012)

Photometric immersion refractometry: a method for determining the refractive index of marine microbial particles from beam attenuation

Miroslaw Jonasz, Georges Fournier, and Dariusz Stramski
Appl. Opt. 36(18) 4214-4225 (1997)