A Fourier Transform Spectrometer (FTS) is an instrument used to measure the spectral content of light. It works by collecting light from a source and splitting it into different wavelengths. The FTS then uses a technique called the Fourier Transform to convert the time-domain signal into a frequency-domain spectrum, allowing for detailed analysis of the light's properties. FTS is widely used in various fields, including chemistry, physics, and astronomy. It provides high-resolution spectra and can analyze a wide range of wavelengths, making it valuable for identifying chemical compounds and studying materials.