Built-up alignment system by four-quadrant detector in high power laser system

Spatial stability is an important property of a laser beam for a laser system. Because four-quadrant detector has more high damage threshold than CCD, it can be applied in a high laser system to monitor the direction of laser beam. In this article, the four-quadrant detector as pointing monitor device is used for a 532nm semiconductor laser, which can obtain the center position of laser spot quickly. In the experiment, the amount of shift and jitter for laser beam is measured at first. Next step is combining rotating stage and lens to measure the alignment error for three angles. The results show that the top amount of shift and jitter is 3.6 " and the average of combined pointing error is around 6 ". The data can support the spatial beam pointing stability system which needs feedback system with fast steering mirrors.