FPGA adaptive optics system test bench

摘要

FPGA (Field Programmable Gate Array) technology has become a very powerful tool available to the electronic designer, specially after the spreading of high quality synthesis and simulation software packages at very affordable prices. They also offer high physical integration levels and high speed, and eases the implementation of parallelism to obtain superb features. Adaptive optics for the next generation telescopes (50-100 m diameter) -or improved versions for existing ones-requires a huge amount of processing power that goes beyond the practical limits of today's processor capability, and perhaps tomorrow's, so FPGAs may become a viable approach. In order to evaluate the feasibility of such a system, a laboratory adaptive optical test bench has been developed, using only FPGAs in its closed loop processing chain. A Shack-Hartmann wavefront sensor has been implemented using a 955-image per second DALSA CA-D6 camera, and a 37-channel OKO mirror has been used for wavefront correcting. Results are presented and extrapolation of the behavior for large and extremely large telescopes is discussed.