Advanced quantum techniques for future gravitational-wave detectors

Yanbei Chen, S. L. Danilishin, Farid Ya Khalili +1 more

L. Barsotti

S. L. Danilishin, Farid Ya. Khalili, Haixing Miao

Quantum fluctuation of light limits the sensitivity of advanced laser interferometric gravitational-wave detectors. It is one of the principal obstacles on the way towards the next-generation gravitational-wave observatories. The envisioned significant improvement of the detector sensitivity requires using quantum non-demolition measurement and back-action evasion techniques, which allow us to circumvent the sensitivity limit imposed by the Heisenberg uncertainty principle. In our previous review article (Danilishin and Khalili in Living Rev Relativ 15:5, 2012 ), we laid down the basic principles of quantum measurement theory and provided the framework for analysing the quantum noise of interferometers. The scope of this paper is to review novel techniques for quantum noise suppression proposed in the recent years and put them in the same framework. Our delineation of interferometry schemes and topologies is intended as an aid in the process of selecting the design for the next-generation gravitational-wave observatories.

Farit Ya. Khalili

Farid Ya Khalili

Mengyao Wang

Gravitational waves are a predication of Einstein's theory of general relativity. After nearly 50 years of effort by the scientific community to construct a detector capable of directly measuring gravitational waves, we expect a breakthrough, the first ever direct measurement of a gravitational wave within the next 5 years. The Advanced LIGO detectors currently under construction are predicted to achieve not only the first detection but to open the field of gravitational-wave astronomy: as an observational window on astrophysics and with an impart on other areas such as cosmology, strong-field gravity, general relativity, and nuclear physics. \n \nThe Advanced LIGO detectors are large-scale laser interferometers that have been designed for very low technical noise so that quantum noise will be limiting their sensitivity over a wide range of their spectrum. Planning for future gravitational wave observatories is already underway and reducing the fundamental quantum noise is considered to be one of the main experimental challenges. My work over the last 4 years has focused on possible new techniques to reduce or circumvent the quantum noise in laser interferometers. \n