Absolute distance sensing by two laser optical interferometry

作者：Thurner Klaus^*; Braun Pierre Francois; Karrai Khaled

来源：Review of Scientific Instruments, 2013, 84(11): 115002.

DOI：10.1063/1.4831800

We have developed a method for absolute distance sensing by two laser optical interferometry. A particularity of this technique is that a target distance is determined in absolute and is no longer limited to within an ambiguity range affecting usually multiple wavelength interferometers. We implemented the technique in a low-finesse Fabry-Perot miniature fiber based interferometer. We used two diode lasers, both operating in the 1550 nm wavelength range. The wavelength difference is chosen to create a 25 mu m long periodic beating interferometric pattern allowing a nanometer precise position measurement but limited to within an ambiguity range of 25 mu m. The ambiguity is then eliminated by scanning one of the wavelengths over a small range (3.4 nm). We measured absolute distances in the sub-meter range and this with just few nanometer repeatability.

• 出版日期2013-11