Enhanced sensitivity of the LIGO gravitational wave detector by using squeezed states of light

• Main Authors: Barsotti, Lisa (Author), Biscans, Sebastien (Author), Bodiya, Timothy P. (Author), Donovan, Frederick J (Author), Dwyer, S. E. (Author), Essick, Reed Clasey (Author), Evans, M. (Author), Foley, Stephany (Author), Fritschel, Peter K. (Author), Gras, Slawomir (Author), Isogai, Tomoki (Author), Katsavounidis, Erotokritos (Author), Kissel, Jeffrey S. (Author), Kwee, Patrick (Author), MacInnis, Myron E (Author), Mason, Kenneth R (Author), Matichard, Fabrice (Author), Mavalvala, Nergis (Author), Mittleman, Richard K (Author), Oelker, Eric Glenn (Author), Sankar, Shannon Reynier (Author), Shoemaker, David H (Author), Vaulin, Ruslan (Author), Vitale, Salvatore (Author), Waldman, Samuel J. (Author), Weiss, Rainer (Author), Wipf, Christopher C. (Author), Zhang, F. (Author), Zucker, Michael E (Author)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor), Lincoln Laboratory (Contributor), LIGO (Observatory : Massachusetts Institute of Technology) (Contributor), MIT Kavli Institute for Astrophysics and Space Research (Contributor)
• Format: Article
• Language: English
• Published: Nature Publishing Group, 2019-06-10T18:37:43Z.
• Subjects: Article
• Online Access: Get fulltext

 Nearly a century after Einstein first predicted the existence of gravitational waves, a global network of Earth-based gravitational wave observatories 1-4 is seeking to directly detect this faint radiation using precision laser interferometry. Photon shot noise, due to the quantum nature of light, imposes a fundamental limit on the attometre-level sensitivity of the kilometre-scale Michelson interferometers deployed for this task. Here, we inject squeezed states to improve the performance of one of the detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) beyond the quantum noise limit, most notably in the frequency region down to 150 Hz, critically important for several astrophysical sources, with no deterioration of performance observed at any frequency. With the injection of squeezed states, this LIGO detector demonstrated the best broadband sensitivity to gravitational waves ever achieved, with important implications for observing the gravitational-wave Universe with unprecedented sensitivity.