Achieving resonance in the Advanced LIGO gravitational-wave interferometer
Abstract
Interferometric gravitational-wave detectors are complex instruments comprised of a Michelson interferometer enhanced by multiple coupled cavities. Active feedback control is required to operate these instruments and keep the cavities locked on resonance. The optical response is highly nonlinear until a good operating point is reached. The linear operating range is between 0.01% and 1% of a fringe for each degree of freedom. The resonance lock has to be achieved in all five degrees of freedom simultaneously, making the acquisition difficult. Furthermore, the cavity linewidth seen by the laser is only _(~1) Hz, which is four orders of magnitude smaller than the linewidth of the free running laser. The arm length stabilization system is a new technique used for arm cavity locking in Advanced LIGO. Together with a modulation technique utilizing third harmonics to lock the central Michelson interferometer, the Advanced LIGO detector has been successfully locked and brought to an operating point where detecting gravitational-waves becomes feasible.
Additional Information
© 2014 IOP Publishing Ltd. Received 25 July 2014, revised 12 September 2014. Accepted for publication 26 September 2014. Published 26 November 2014. We would like to thank the staff at the LIGO Hanford Observatory and the LIGO Livingston Observatory for their unrelenting support, and extend our thanks to the entire Advanced LIGO team for building and installing the two instruments. 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. The authors also gratefully acknowledge the support from the Australian Research Council, the International Science Linkages program of the Commonwealth of Australia. AS would like to thank Columbia University in the City of New York for its support. This paper carries LIGO Document Number LIGO-P1400105. The research is supported by the National Natural Science Foundation of China under grant no. 10865002 and no. 11265004.Additional details
- Eprint ID
- 53209
- DOI
- 10.1088/0264-9381/31/24/245010
- Resolver ID
- CaltechAUTHORS:20150106-115959765
- PHY-0757058
- NSF
- Australian Research Council
- International Science Linkages program of the Commonwealth of Australia
- Columbia University in the City of New York
- 10865002
- National Natural Science Foundation of China
- 11265004
- National Natural Science Foundation of China
- Created
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2015-01-06Created from EPrint's datestamp field
- Updated
-
2022-07-12Created from EPrint's last_modified field
- Other Numbering System Name
- LIGO-Document Number
- Other Numbering System Identifier
- P1400105