We designed wide FoV (1 degree) Nasmyth optics which transformed the f/6 Nasmyth focus to f/1 at a 850GHz superconducting camera for a planning 10-m Ritchey-Chrétien telescope. This optical system consists of reflecting mirrors at room temperature and a refractive lens at 4K. It enables us to carry out wide FoV imaging observations at the diffraction limit (Strehl ratio < 0.89) with a more than 100,000 pixel camera equipped in a 10-m telescope. The size of this system is reasonably compact (whole size:1.6 mx3.3 mx2.6 m, cryogenic part:0.7 mx0.7 mx1.0 m). The cryogenic part of this system such as vacuum window, cryogenic lens and IR block filters can be made with existing technologies at reasonable cost. The optical system can extend to the millimeter wave and the terahertz domain.

Date Published: 23 July 2014
PDF: 6 pages
Proc. SPIE 9153, Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII, 91532U (23 July 2014); doi: 10.1117/12.2055694

Published in SPIE Proceedings Vol. 9153:
Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII
Wayne S. Holland; Jonas Zmuidzinas, Editor(s)