Diode-laser-based high-precision absolute distance interferometer of 20 m range

Appl Opt. 2009 Nov 10;48(32):6188-94. doi: 10.1364/AO.48.006188.

Abstract

We present a hybrid absolute distance measurement method that is based on a combination of frequency sweeping, variable synthetic, and two-wavelength, fixed synthetic wavelength interferometry. Both experiments were realized by two external cavity diode lasers. The measurement uncertainty was experimentally and theoretically demonstrated to be smaller than 12 microm at a measurement distance of 20 m.