Fiber optic probes collect light or spectra from extreme environments inside reaction vessels at high temperatures or pressures. Product types include UV-Vis spectroscopy probes, Raman spectroscopy probes, and refractometry probes. UV-Vis spectroscopy probes track the electronic transitions of molecules as they absorb light in the ultraviolet (UV) and visible (Vis) regions of the electromagnetic spectrum. These fiber optic probes can be used with a wide range of samples and are suitable for biochemical, biological, and pharmaceutical research. Raman spectroscopy probes collect scattered light from a sample that is illuminated with a laser. Molecular components are identified through an analysis of the wavelengths and intensities of the scattered light. Because of their ability to avoid sample contamination, Raman spectroscopy probes are often used in polymer and semiconductor applications. Refractometry probes are fiber optic probes that detect the deviation of light by a solution as a measure of specific gravity. They are sometimes used in the identification of gemstones.