Design of a compact four degree-of-freedom active compensation system to restrain laser's angular drift and parallel drift.

The laser collimation technique is widely used in science research and industrial applications. The pointing stability will be affected by the common problem of beam drift. A compact active compensation system is presented in this paper. The angular drift of the diode laser and parallel shift caused by angular drift compensation can be measured and actively compensated through a 4 degree-of-freedom active compensation module. The design of the whole system is compact, which makes it easy to be integrated into a measurement system. Experimental results indicate that the approach proposed can enhance the point stability to 88% for only angular drift compensation and further to 96.1% if both angular drift and parallel shift are compensated. This compensation module for point stability control can be used in any laser applications. [ABSTRACT FROM AUTHOR]