Near‐infrared fiber‐optic sample cell: Applications to fourier transform Raman and near‐infrared absorption and reflectance spectroscopies

A fiber‐optic sample cell designed for use in the near‐infrared region is described. For Fourier transform (FT) Raman spectroscopy, Nd:YAG laser radiation is transmitted to the sample through one fiber bundle, while a second fiber bundle collects and transfers the scattered light to the source compartment of an infrared interferometer equipped with a CaF 2 beam splitter and an InGaAs detector. Because the two fiber bundles are mounted in the aluminum body of the cell, virtually no optical alignment is required. In addition to its utility in FT‐Raman spectroscopy, the cell may be used for obtaining near‐infrared absorption spectra of liquids and reflectance spectra of solids without changing its configuration. Examples of the many uses of the cell are provided, and modifications which would potentially improve its efficiency and expand its capabilities are discussed.