Mach-Zehnder interferometer [`mäk `tsān·dǝr ´in·tǝr·fǝ`räm·ǝd·ǝr] OPTICS A variation of the Michelson interferometer used mainly in measuring the spatial variation of the index of refraction of a gas; the device has two semitransparent mirrors and two wholly reflecting mirrors at alternate corners of a rectangle, and half the beam travels along each side of the rectangle. Also known as Mach refractometer. |