Demonstration of an amplitude filter cavity at gravitational-wave frequencies

Abstract

Quantum vacuum fluctuations fundamentally limit the precision of optical measurements, such as those in gravitational-wave detectors. Injection of conventional squeezed vacuum can be used to reduce quantum noise in the readout quadrature, but this reduction is at the cost of increasing noise in the orthogonal quadrature. For detectors near the limits imposed by quantum radiation pressure noise (QRPN), both quadratures impact the measurement, and the benefits of conventional squeezing are limited. In this paper, we demonstrate the use of a critically-coupled 16m optical cavity to diminish anti-squeezing at frequencies below 90Hz where it exacerbates QRPN, while preserving beneficial squeezing at higher frequencies. This is called an amplitude filter cavity, and it is useful for avoiding degradation of detector sensitivity at low frequencies. The attenuation from the cavity also provides technical advantages such as mitigating backscatter.

7 pages, 4 figures

References in corpus (8)

• Advanced LIGO
• Sideband Cooling Micromechanical Motion to the Quantum Ground State
• Quantum correlations between the light and kilogram-mass mirrors of LIGO
• Frequency-Dependent Squeezing for Advanced LIGO
• Prospects for doubling the range of Advanced LIGO
• Experimental characterization of frequency dependent squeezed light
• Frequency-Dependent Squeezed Vacuum Source for Broadband Quantum Noise Reduction in Advanced Gravitational-Wave Detectors
• Optimal detuning for quantum filter cavities

Cited by in corpus (5)

• Review of the Advanced LIGO gravitational wave observatories leading to observing run four
• LIGOs Quantum Response to Squeezed States
• Optimal detuning for quantum filter cavities
• Enhancing high frequency sensitivity of gravitational wave detectors with sloshing-Sagnac interferometer
• Probing squeezing for gravitational-wave detectors with an audio-band field