Linear refractive index and absorption measurements of nonlinear optical liquids in the visible and near-infrared spectral region

TLDR

Liquid‑filled photonic crystal fibers and optofluidic devices require infiltration with liquids whose linear optical properties are poorly known across a broad spectral range, especially in the near‑infrared. The authors measured dispersion and absorption of distilled water, heavy water, chloroform, carbon tetrachloride, toluene, ethanol, carbon disulfide, and nitrobenzene between 500 nm and 1750 nm at 20 °C using an Abbe refractometer with a white‑light laser and correction for prism dispersion, and derived absorption coefficients from loss differences in identically prepared liquid‑filled glass cells of varying lengths. New refractive index data and dispersion formulas for 500–1600 nm agree with sparse reference data, and absorption spectra for 500–1750 nm are reported.

Abstract

Liquid-filled photonic crystal fibers and optofluidic devices require infiltration with a variety of liquids whose linear optical properties are still not well known over a broad spectral range, particularly in the near infrared. Hence, dispersion and absorption properties in the visible and near-infrared wavelength region have been determined for distilled water, heavy water, chloroform, carbon tetrachloride, toluene, ethanol, carbon disulfide, and nitrobenzene at a temperature of 20 °C. For the refractive index measurement a standard Abbe refractometer in combination with a white light laser and a technique to calculate correction terms to compensate for the dispersion of the glass prism has been used. New refractive index data and derived dispersion formulas between a wavelength of 500 nm and 1600 nm are presented in good agreement with sparsely existing reference data in this wavelength range. The absorption coefficient has been deduced from the difference of the losses of several identically prepared liquid filled glass cells or tubes of different lengths. We present absorption data in the wavelength region between 500 nm and 1750 nm.