An experimental Rayleigh laser guide star ground layer adaptive optics system for the William Herschel telescope

The design of an experimental ground layer adaptive optics (GLAO) system that uses a low altitude Rayleigh laser guide star as a wavefront reference source is presented. GLAO is a technique for achieving wide-field partial adaptive optics correction of the aberrations in a wavefront due to the effects of propagation through a turbulent atmosphere. The theoretical performance of the GLAO sub-systems, such as the laser launch system, wavefront sensor and optical train are analysed and compared, where possible, to measurements taken both under laboratory conditions and on-sky at the William Herschel Telescope.