Scalable MWIR and LWIR optical system designs employing a large spherical primary mirror and small refractive aberration correctors

David A. Beach

doi:10.1117/12.449561

5 December 2001 Scalable MWIR and LWIR optical system designs employing a large spherical primary mirror and small refractive aberration correctors

David A. Beach

Author Affiliations +

Proceedings Volume 4441, Current Developments in Lens Design and Optical Engineering II; (2001) https://doi.org/10.1117/12.449561
Event: International Symposium on Optical Science and Technology, 2001, San Diego, CA, United States

Abstract

Design variants of a recently developed optical imaging system have been computed for the thermal infrared spectral bands, which offer some advantages for long-range surveillance and astronomy. Only the spherical primary mirror has the full pupil diameter, all other components being sub-diameter, so scaling is possible up to relatively large pupils. Low-cost fabrication is enabled by the prevalence of spherical optical surfaces. Both MWIR and LWIR spectral transmissions are enabled by the choice of corrector materials, the examples given employing germanium and sapphire for 3.5 - 5.5 micrometers and germanium and zinc selenide for 3.5 - 5.5 micrometers and 8 - 12 micrometers passbands. Diffraction at these wavelengths is the main contributor to resolution constraints, so high numerical aperture values are preferred to enable a better match of blur spot diameter to generally available pixel dimensions. The systems described can routinely be designed to have speeds of f/0.8 or faster, while maintaining diffraction-limited performance over useful angular fields. Because the new design system employs a relayed catadioptric, it is possible to make the aperture stop of the system coincident with the window of the detector cryostat, enabling precise radiometric geometry. The central obscuration provides a convenient location for a calibration source, and both this and a mask for secondary spider supports can be included within the detector cold screen structure. Dual-band operation could be enabled by inclusion of a spectral beam splitter prior to a dual relay/imager system.

Citation Download Citation

David A. Beach "Scalable MWIR and LWIR optical system designs employing a large spherical primary mirror and small refractive aberration correctors", Proc. SPIE 4441, Current Developments in Lens Design and Optical Engineering II, (5 December 2001); https://doi.org/10.1117/12.449561

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
9 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Long wavelength infrared

Mid-IR

Spherical lenses

Mirrors

Sapphire

Relays

Imaging systems

Show All Keywords

Keywords/Phrases

Search In:

Publication Years