| has gloss | eng: A Twyman–Green interferometer is a variant of the Michelson interferometer principally used to test optical components. The setup of the Twyman-Green interferometer is similar to that of the Michelson interferometer (cf. same for a picture of the setup). There are two differences between the Michelson and Twyman–Green interferometers. First, the fixed mirror in the Michelson interferometer is rotatable in the Twyman–Green interferometer, and second, while the light source is usually an extended source (although it can also be a laser) in a Michelson interferometer, the light source is always a point-like source in the Twyman–Green interferometer. |