Optical Beam Steering On Distribution Boards And Its Application For Atom Quantum Experiments In Space

We present a novel optical beam steering technique (OBST) for fiber to free-space to fiber coupling schemes on optical breadboards, which uses glass wedge pairs and plates to correct for angular and translational misalignments respectively. This technique finds application in proposed missions for atom quantum experiments in space, e.g. where laser beams are used to cool and manipulate atomic clouds. The key advantage compared to the conventional beam steering is that OBST permits extremely fine adjustments whilst being far less sensitive to alignment errors and mechanical drifts. Beam steering resolutions of better than 5 mu rad and 2 mu m are achieved, resulting in a resolution in coupling efficiency (CE) of 0.1%. The inclusion of OBST on an optical breadboard reduces the requirements on the pointing and position precision adjustment of the fiber couplers, leading to a much-simplified design. The simpler construction of the couplers combined with the reduced sensitivity to drifts increases the stability-reliability of the breadboard and reduces the production duration and cost. We demonstrate CE of up to 90%, with a stability of 0.2% in a stable temperature environment and 2% over a temperature range from 10-40 degrees Celsius. We do not observe any change in the performance after large temperature changes.