Fourier Transform Spectroscopy (FTS).

The article presents information on Fourier transform spectroscopy (FTS). A. A. Michelson invented in the 1880s a simple interferometer, which basically consists of a beamsplitter and two plane mirrors. Initially, the interferometer was used to study the speed of light and to fix the standard meter with the wavelength of a spectral line. The Michelson interferometer is very simple, but its principles of function can be applied to other interferometers used in Fourier transform spectroscopy, FTS. The incident beam is divided by a beamsplitter B into two parts: the reflected beam travels to a fixed mirror and back, and the transmitted beam travels to a moving mirror and back.