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WaFIRS: a waveguide far-IR spectrometer: enabling spectroscopy of high-z galaxies in the far-IR and submillimeter

Bradford, C. M. and Naylor, B. J. and Zmuidzinas, J. and Bock, J. J. and Gromke, J. and Nguyen, H. and Dragovan, M. and Yun, M. and Earle, L. and Glenn, J. and Matsuhara, H. and Ade, P. A. R. and Duband, L. (2003) WaFIRS: a waveguide far-IR spectrometer: enabling spectroscopy of high-z galaxies in the far-IR and submillimeter. In: IR Space Telescopes and Instruments. Proceedings of SPIE. No.4850. Society of Photo-optical Instrumentation Engineers (SPIE) , Bellingham, WA, pp. 1137-1148. ISBN 9780819446299.

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The discovery of galaxies beyond z~1 which emit the bulk of their luminosity at long wavelengths has demonstrated the need for high-sensitivity, broad-band spectroscopy in the far-IR/submm/mm bands. Because many of these sources are not detectable in the optical, long-wavelength spectroscopy is key to measuring their redshifts and ISM conditions. The continuum source list will increase in the coming decade with new ground-based instruments (SCUBA2, Bolocam, MAMBO), and the surveys of HSO and SIRTF. Yet the planned spectroscopic capabilities lag behind, in part due to the difficulty in scaling existing IR spectrograph designs to longer wavelengths. To overcome these limitations, we are developing WaFIRS, a novel concept for long-wavelength spectroscopy which utilizes a parallel-plate waveguide and a curved diffraction grating. WaFIRS provides the large (~60%) instantaneous bandwidth and high throughput of a conventional grating system, but offers a dramatic reduction in volume and mass. WaFIRS requires no space overheads for extra optical elements beyond the diffraction grating itself, and is two-dimensional because the propagation is confined between two parallel plates. Thus several modules could be stacked to multiplex either spatially or in different frequency bands. The size and mass savings provide opportunities for spectroscopy from space-borne observatories which would be impractical with traditional spectrographs. With background-limited detectors and a cooled 3.5 m telescope, the line sensitivity would be comparable to that of ALMA, with instantaneous broad-band coverage. We present the spectrometer concept, performance verification with a mm-wave prototype, and our progress toward a cryogenic astronomical instrument.

Item Type:Book Section
Related URLs:
URLURL TypeDescription
Bradford, C. M.0000-0001-5261-7094
Bock, J. J.0000-0002-5710-5212
Glenn, J.0000-0001-7527-2017
Ade, P. A. R.0000-0002-5127-0401
Additional Information:© 2003 Society of Photo-optical Instrumentation Engineers (SPIE). We are grateful to Peter Siegel at JPL for his generous help with the backward wave oscillator. We would like to acknowledge support from the JPL Director’s R&D Fund, sponsored by NASA. JG also acknowledges NASA (NAG5-11911) and the Research Corporation (RI 0928).CMB is supported in part with a Millikan Fellowship at CIT.
Funding AgencyGrant Number
JPL Director’s Research and Development FundUNSPECIFIED
Research CorporationRI 0928
Robert A. Millikan FellowshipUNSPECIFIED
Subject Keywords:far-IR, spectroscopy, waveguide, grating, planar spectrometer
Series Name:Proceedings of SPIE
Issue or Number:4850
Record Number:CaltechAUTHORS:20190118-151006155
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Official Citation:Charles M. Bradford, Bret J. Naylor, Jonas Zmuidzinas, James J. Bock, J. Gromke, Hien Nguyen, Mark Dragovan, Minhee Yun, Lieko Earle, Jason Glenn, Hideo Matsuhara, Peter A. R. Ade, Lionel Duband, "WaFIRS: a waveguide far-IR spectrometer enabling spectroscopy of high-z galaxies in the far-IR and submillimeter," Proc. SPIE 4850, IR Space Telescopes and Instruments, (5 March 2003); doi: 10.1117/12.461572
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:92379
Deposited By: Tony Diaz
Deposited On:22 Jan 2019 04:47
Last Modified:09 Mar 2020 13:18

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