A PC-interfaced, compact laser-diode feedback interferometer for displacement measurements

Abstract

We describe a laser-diode feedback interferometer for displacement measurements with directional discrimination and resolution better than 10~6 m. This new, compact instrument consists of a small optical head and a signal processing board, which is interfaced to a personal computer. The prototype developed has a dynamic range of 2 m and an accuracy of about 5 /um/m, using a corner cube as a remote reflector. Thanks to PC interfacing, the displacement is directly available in metric units and errors due to temperature fluctuations can be corrected with software signal processing. © 1996 IEEE.