Feedback interferometry with semiconductor laser for high-resolution displacement sensing

We present the prototype of a laser feedback interferometer for displacement measurement with micrometric resolution and directional discrimination, which we propose for applications in industrial environment. The instrument incorporates a PC-interfaced electronic unit connected with the optical head, which is very compact thanks to the selected optical configuration and to the use of a semiconductor laser. Infrared as well as red emitting lasers have been used for operation on reflecting and diffusing targets.