Alignment and performance of the Infrared Multi-Object Spectrometer

Joseph A. Connelly; Raymond G. Ohl; J. Eric Mentzell; Timothy J. Madison; Jason E. Hylan; Ronald G. Mink; Timo T. Saha; June L. Tveekrem; Leroy M. Sparr; Victor John Chambers; Danette L. Fitzgerald; Matthew A. Greenhouse; John W. MacKenty

doi:10.1117/12.503984

15 October 2003 Alignment and performance of the Infrared Multi-Object Spectrometer

Joseph A. Connelly, Raymond G. Ohl, J. Eric Mentzell, Timothy J. Madison, Jason E. Hylan, Ronald G. Mink, Timo T. Saha, June L. Tveekrem, Leroy M. Sparr, Victor John Chambers, Danette L. Fitzgerald, Matthew A. Greenhouse, John W. MacKenty

Author Affiliations +

Proceedings Volume 5172, Cryogenic Optical Systems and Instruments X; (2003) https://doi.org/10.1117/12.503984
Event: Optical Science and Technology, SPIE's 48th Annual Meeting, 2003, San Diego, California, United States

Abstract

The Infrared Multi-Object Spectrometer (IRMOS) is a principle investigator class instrument for the Kitt Peak National Observatory 4 and 2.1 m telescopes. IRMOS is a near-IR (0.8 - 2.5 μm) spectrometer with low- to mid-resolving power (R = 300 - 3000). IRMOS produces simultaneous spectra of ~100 objects in its 2.8 - 2.0 arc-min field of view (4 m telescope) using a commercial Micro Electro-Mechanical Systems (MEMS) micro-mirror array (MMA) from Texas Instruments. The IRMOS optical design consists of two imaging subsystems. The focal reducer images the focal plane of the telescope onto the MMA field stop, and the spectrograph images the MMA onto the detector. We describe ambient breadboard subsystem alignment and imaging performance of each stage independently, and ambient imaging performance of the fully assembled instrument. Interferometric measurements of subsystem wavefront error serve as a qualitative alignment guide, and are accomplished using a commercial, modified Twyman-Green laser unequal path interferometer. Image testing provides verification of the optomechanical alignment method and a measurement of near-angle scattered light due to mirror small-scale surface error. Image testing is performed at multiple field points. A mercury-argon pencil lamp provides a spectral line at 546.1 nm, a blackbody source provides a line at 1550 nm, and a CCD camera and IR camera are used as detectors. We use commercial optical modeling software to predict the point-spread function and its effect on instrument slit transmission and resolution. Our breadboard and instrument level test results validate this prediction. We conclude with an instrument performance prediction for cryogenic operation and first light in late 2003.

Citation Download Citation

Joseph A. Connelly, Raymond G. Ohl, J. Eric Mentzell, Timothy J. Madison, Jason E. Hylan, Ronald G. Mink, Timo T. Saha, June L. Tveekrem, Leroy M. Sparr, Victor John Chambers, Danette L. Fitzgerald, Matthew A. Greenhouse, and John W. MacKenty "Alignment and performance of the Infrared Multi-Object Spectrometer", Proc. SPIE 5172, Cryogenic Optical Systems and Instruments X, (15 October 2003); https://doi.org/10.1117/12.503984

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