An off-axis, wide-field, diffraction-limited, reflective Schmidt Telescope

• Main Author: Saunders, Will
• Format: Text
• Language: unknown
• Published: arXiv 2010
• Subjects: Instrumentation and Methods for Astrophysics astro-ph.IM; FOS Physical sciences; Antarctic; The Antarctic; Antarc*
• Online Access: https://dx.doi.org/10.48550/arxiv.1008.1235; https://arxiv.org/abs/1008.1235

Off-axis telescopes with unobstructed pupils offer great advantages in terms of emissivity, throughput, and diffractionlimited energy concentration. For most telescope designs, implementation of an off-axis configuration imposes enormous penalties in terms of cost, optical difficulty and performance, and for this reason off-axis telescopes are rarely constructed. However, for the reflective Schmidt design, implementation of an off-axis configuration is very straightforward, and involves only a modest optical penalty. Moreover, the reflective Schmidt gets particular benefits, avoiding the obstruction of its large focal plane and support column, and gaining a highly accessible, gravity-invariant prime focus, capable of accommodating very large instrumentation. We present an off-axis f/8 reflective Schmidt design for the proposed 'KDUST' Chinese infrared telescope at Dome A on the Antarctic plateau, which offers simultaneous diffraction-limited NIR imaging over 1 degree, and close to diffraction-limited imaging out to 2 degrees for fibre-fed NIR spectroscopy. : 7 pages, Proc. SPIE 7733-118