• DOI:10.1103/PhysRevLett.110.181101
• Corpus ID: 3566080

First long-term application of squeezed states of light in a gravitational-wave observatory.

@article{Grote2013FirstLA,
  title={First long-term application of squeezed states of light in a gravitational-wave observatory.},
  author={Hartmut Grote and Karsten Danzmann and K L Dooley and Roman Schnabel and Jacob Slutsky and Henning Vahlbruch},
  journal={Physical review letters},
  year={2013},
  volume={110 18},
  pages={
          181101
        }
}

• H. Grote, K. Danzmann, +3 authors H. Vahlbruch
• Published 8 February 2013
• Physics
• Physical review letters

We report on the first long-term application of squeezed vacuum states of light to improve the shot-noise-limited sensitivity of a gravitational-wave observatory. In particular, squeezed vacuum was applied to the German-British detector GEO 600 during a period of three months from June to August 2011, when GEO 600 was performing an observational run together with the French-Italian Virgo detector. In a second period, the squeezing application continued for about 11 months from November 2011 to October 2012. During this time, squeezed vacuum was applied for 90.2% (205.2 days total) of the time that science-quality data were acquired with GEO 600. A sensitivity increase from squeezed vacuum application was observed broadband above 400 Hz. The time average of gain in sensitivity was 26% (2.0 dB), determined in the frequency band from 3.7 to 4.0 kHz. This corresponds to a factor of 2 increase in the observed volume of the Universe for sources in the kHz region (e.g., supernovae, magnetars). We introduce three new techniques to enable the long-term application of squeezed light, and show that the glitch rate of the detector did not increase from squeezing application. Squeezed vacuum states of light have arrived as a permanent application, capable of increasing the astrophysical reach of gravitational-wave detectors.