Outdoors phasing progress of dispersed fringe sensing technology in NIAOT, China

Abstract

A telescope with a larger primary mirror can collect much more light and resolve objects much better than one with a smaller mirror, and so the larger version is always pursued by astronomers and astronomical technicians. Instead of using a monolithic primary mirror, more and more large telescopes, which are currently being planned or in construction, have adopted a segmented primary mirror design. Therefore, how to sense and phase such a primary mirror is a key issue for the future of extremely large optical/infrared telescopes. The Dispersed Fringe Sensor is a non-contact method using broadband point light sources and it can estimate the piston by the two-directional spectrum formed by the transmissive grating's dispersion and lenslet array. In this paper we introduce you the current research progress of the successful design, construction and alignment of our dispersed Hartmann sensors together with its design principles and simulations for indoor segmented mirror experiment system and outdoor segmented mirror experiment system. We also conduct many successful real phasing tests and phasing corrections in the visible waveband using our existing indoor and outdoor segmented mirror optics platform. Finally, some conclusions are reached based on the test and correction of experimental results.