title: Two-wavelength double heterodyne interferometry using a matched grating technique.
abstract: Two-wavelength double heterodyne interferometry is applied for topographic measurements on optically rough target surfaces. A two-wavelength He-Ne laser and a matched grating technique are used to improve system stability and to simplify heterodyne frequency generation.
authors: Z
authors: Z
authors: Sodnik
authors: E
authors: E
authors: Fischer
authors: T
authors: T
authors: Ittner
authors: H J
authors: HJ
authors: Tiziani