Optical design of an achromatic re-imaging lens system for a cryogenic near-infrared astronomical camera

Suzanne Casement; Ian S. McLean; Robert E. Fischer

doi:10.1117/12.158708

20 October 1993 Optical design of an achromatic re-imaging lens system for a cryogenic near-infrared astronomical camera

Suzanne Casement, Ian S. McLean, Robert E. Fischer

Author Affiliations +

Proceedings Volume 1946, Infrared Detectors and Instrumentation; (1993) https://doi.org/10.1117/12.158708
Event: Optical Engineering and Photonics in Aerospace Sensing, 1993, Orlando, FL, United States

Abstract

This paper describes an infrared imaging system developed to match the physical pixel sizes of the near infrared arrays used in the UCLA IR camera to the typical seeing disk at the f/15 focus of the W. M. Keck telescope. A field of view of 64 arcseconds (') at 0.25' per pixel is required, no internal focussing mechanism is possible and the system must perform under vacuum at 77 K. In our design, an achromatic triplet lens of calcium and barium fluoride provides an image of the entrance pupil and collimates the beam before it passes through a dichroic beam-splitter which divides the system into two independent channels; the wavelength split occurs at approximately 2.5 micrometers . Each beam is re-imaged onto IR arrays with 30 and 40 micrometers pixels to yield 0.25'/pixel and each imager is independently optimized to be achromatic and aberration free. Spot diagrams and aberration plots will be given. We also describe the steps required to compensate for environmental changes, since these lenses are used at LN₂ temperature, and we discuss AR coatings and throughput.

Citation Download Citation

Suzanne Casement, Ian S. McLean, and Robert E. Fischer "Optical design of an achromatic re-imaging lens system for a cryogenic near-infrared astronomical camera", Proc. SPIE 1946, Infrared Detectors and Instrumentation, (20 October 1993); https://doi.org/10.1117/12.158708

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