DC readout experiment in Enhanced LIGO
Abstract
The two 4 km long gravitational wave detectors operated by the Laser Interferometer Gravitational-wave Observatory (LIGO) were modified in 2008 to read out the gravitational wave channel using the DC readout form of homodyne detection and to include an optical filter cavity at the output of the detector. As part of the upgrade to Enhanced LIGO, these modifications replaced the radio-frequency (RF) heterodyne system used previously. We describe the motivations for and the implementation of DC readout and the output mode cleaner in Enhanced LIGO. We present characterizations of the system, including measurements and models of the couplings of the noises from the laser source to the gravitational wave readout channel. We show that noise couplings using DC readout are improved over those for RF readout, and we find that the achieved shot-noise-limited sensitivity is consistent with modeled results.
Additional Information
© 2012 IOP Publishing Ltd. Received 13 October 2011, in final form 31 January 2012. Published 23 February 2012. TF thanks the National Science Foundation for support under grant PHY-0905184 and Caltech for support via the LIGO Visitors Program. The authors would like to thank Koji Arai, Hartmut Grote, David Shoemaker and Zach Korth for comments on this manuscript; and everyone who contributed to the Enhanced LIGO effort. LIGO was constructed by the California Institute of Technology and Massachusetts Institute of Technology with funding from the National Science Foundation and operates under cooperative agreement PHY-0757058. This paper has LIGO Document Number P1000009.Additional details
- Eprint ID
- 29940
- DOI
- 10.1088/0264-9381/29/6/065005
- Resolver ID
- CaltechAUTHORS:20120403-065540150
- PHY-0905184
- NSF
- PHY-0757058
- NSF
- Created
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2012-04-03Created from EPrint's datestamp field
- Updated
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2022-07-12Created from EPrint's last_modified field
- Other Numbering System Name
- LIGO Document Number
- Other Numbering System Identifier
- P1000009