Spectroscopy of tissues can be implemented using optical fibers. An optical fiber spectrometer can operate on the surface of a tissue, such as measurements of skin, the oral mucosa, the gastrointestinal tract, and other tissues surfaces. It can also be implemented as an embedded fiber measurement within a solid tissue, for example, a single fiber within a needle that both delivers and collects light, or as two fibers, one source and one collector, within separate needles that are positioned some distance apart, for assessment of solid organs like a muscle, liver, kidney or brain.
In this report, a simple optical fiber spectrometer is described. Its calibration is presented. Examples of its use are shown in esophageal tissues and in sarcoids on the skin of horses.