Laser interferometers use the precise wavelength of lasers to perform high-precision measurements of distance, angles, and other quantities. There are two main types: homodyne laser interferometers, which are based on Michelson interferometry, and heterodyne laser interferometers, which detect Doppler shifts. Key components include a laser source, beam splitters, retroreflectors, and a measurement receiver. Applications include measuring displacement, angles, flatness, straightness, and vibrations in fields like engineering and manufacturing.