The optical design for Cryoscope: a wide-field NIR telescope with low thermal emission

Jason Fucik; Roger Smith

doi:10.1117/12.2630557

29 August 2022 The optical design for Cryoscope: a wide-field NIR telescope with low thermal emission

Jason Fucik, Roger Smith

Proceedings Volume 12182, Ground-based and Airborne Telescopes IX; 121823N (2022) https://doi.org/10.1117/12.2630557
Event: SPIE Astronomical Telescopes + Instrumentation, 2022, Montréal, Québec, Canada

Abstract

We present the optical design for Cryoscope, a 0.26 m aperture telescope that is a f/2 objective operating over the photometric K band (1.99 to 2.55 μm) with diffraction limited imaging. It has a 16 deg² FoV with a 7.1′′/pix plate scale on a 2048×2048 18 μm/pixel Teledyne H2RG detector array. The objective is a catadioptric design incorporating two thin fused silica meniscus lenses near the entrance aperture, a spherical primary mirror, and a doublet immediately in front of the detector to flatten the image surface. The design solution is capable of delivering diffraction limited images over a 10° field diameter at f/1.25 in the NIR. The use of fused silica for the first two lens elements allows the design to be used for a broad range of applications from the vacuum ultraviolet to thermal IR with only re-optimization of the field flattening doublet. In the VUV (185 to 300 nm) the design is no longer diffraction limited, but can still be made to be pixel limited with detector arrays having pixels as small as 10 μm. The design provides a compact, wide field, and fast objective that can scale to a 1 m-class telescope and offers several benefits over a classical Schmidt telescope. The convex fused silica meniscus lens is strong enough to serve as a vacuum window allowing the entire optical path to be cryogenically cooled to maintain low thermal emission while delivering two orders of magnitude larger field of view than previous ground-based designs for the thermal infrared.

Citation Download Citation

Jason Fucik and Roger Smith "The optical design for Cryoscope: a wide-field NIR telescope with low thermal emission", Proc. SPIE 12182, Ground-based and Airborne Telescopes IX, 121823N (29 August 2022); https://doi.org/10.1117/12.2630557

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
13 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Telescopes

Mirrors

Aspheric lenses

Objectives

Sensors

Near infrared

Lenses

Show All Keywords

Keywords/Phrases

Search In:

Publication Years