High-precision and fast-response laser power stabilization system for cold atom experiments

An innovative and practical scheme of building laser power stabilization system is proposed by using external-control method. A high-speed Field Programmable Gate Array (FPGA) is used as real-time controller, which makes the closed-loop control period of only 4.175μs and response time for stabilizing process less than 90μs. The typical noises affecting the laser power is analyzed. Experimental results show that the system has a high stability improvement with stability of output laser keeps around 2‰ whether the input laser is free running or frequency scanning, which proves the competent performance to satisfy high request of laser power stability in cold atom experiments. What’s more, the laser power stabilization system can be embedded as a functional module into the FPGA based timing sequence system in cold atom interferometry, which makes the laser power be controllable accurately by the way of time sequence.