ABSOLUTE INTERFEROMETRIC DISTANCE MEASUREMENTS APPLYING A VARIABLE SYNTHETIC WAVELENGTH

This paper describes the principle and design of a first prototype of an absolute distance interferometer using a variable synthetic wavelen gth. The major components of the prototype are two piezoelectrically t unable diode lasers with an external cavity, and a mechanical dimensio nal standard. Measurements made over distances of several metres in a workshop environment with an averaging time of 5 s gave an uncertainty of +/-10 mu m.