Abstract

A method was developed to obtain the absorption coefficient spectrum of a grain of coal (as small as 10⁻⁷) in the region of aliphatic and aromatic C-H stretching bands (2700-3200 cm⁻¹) using infrared transflection microspectroscopy. In this method, the complex refractive index <i>n</i> − <i>ik</i> was determined using an optimization algorithm with the Kramers-Kronig transform so that the calculated transflection spectrum from the Fresnel equation corresponded to the measured one. The obtained absorption coefficients were compared with the bulk values determined from the potassium bromide (KBr) pellet measurement method.

Method to derive the infrared complex refractive indices n(λ) and k(λ) for organic solids from KBr pellet absorption measurements

Kelly A. Peterson, Ryan M. Francis, Catherine A. Banach, Ashley M. Bradley, Sarah D. Burton, Jeremy D. Erickson, Schuyler P. Lockwood, Karissa L. Jensen, Michael O. Yokosuk, Timothy J. Johnson, and Tanya L. Myers
Appl. Opt. 63(6) 1553-1565 (2024)

The Use of Infrared Spectra of Chars in Coal Structure Research

R. A. Friedel
Appl. Opt. 2(11) 1109-1111 (1963)

The visible and near-infrared optical absorption coefficient spectrum of Parylene C measured by transmitting light through thin films in liquid filled cuvettes

James A. Guggenheim, Yuanyuan Lyu, Dylan M. Marques, Edward Z. Zhang, and Paul C. Beard
Opt. Mater. Express 11(11) 3854-3869 (2021)

Temperature and salinity correction coefficients for light absorption by water in the visible to infrared spectral region

Rüdiger Röttgers, David McKee, and Christian Utschig
Opt. Express 22(21) 25093-25108 (2014)

Method for the determination of the optical properties of highly conjugated pigments

J. L. Musfeldt, D. B. Tanner, and A. J. Paine
J. Opt. Soc. Am. A 10(12) 2648-2657 (1993)