Laser beam angular stabilization system based on a compact interferometer and a precise double-wedge deflector.

To increase the laser beam pointing stability required for precise interferometric measurements, we designed an active laser beam angular stabilization system. We used two recently proposed techniques: an interferometric measurement method of laser beam angular deflection which allows compact sensor design and a double wedge-prism beam deflector for precise laser beam steering. Our system provides long-term angular stabilization independently in the horizontal and the vertical planes, providing a hundredfold reduction of the output beam deviations. First, we describe the compact sensor setup with a new measurement algorithm prepared specifically for our stabilization system. Then, the system is introduced, and experimental evaluation is described. The test results show a good performance for the proposed design. We reached a reduction in beam angular deviations amplitude down to 100 nrad/h (in terms of double standard deviation of beam fluctuations).