A new quantum speed-meter interferometer: measuring speed to search for intermediate mass black holes

Abstract

The recent discovery of gravitational waves (GW) by Advanced LIGO (Laser Interferometric Gravitational-wave Observatory) has impressively launched the novel field of gravitational astronomy and allowed us to glimpse exciting objects about which we could previously only speculate. Further sensitivity improvements at the low-frequency end of the detection band of future GW observatories must rely on quantum non-demolition (QND) methods to suppress fundamental quantum fluctuations of the light fields used to readout the GW signal. Here we present a novel concept of how to turn a conventional Michelson interferometer into a QND speed-meter interferometer with coherently suppressed quantum back-action noise. We use two orthogonal polarizations of light and an optical circulator to couple them. We carry out a detailed analysis of how imperfections and optical loss influence the achievable sensitivity. We find that the proposed configuration significantly enhances the low-frequency sensitivity and increases the observable event rate of binary black-hole coalescences in the range of by a factor of up to ~300.

Quantum noise cancellation in asymmetric speed metres with balanced homodyne readout

“…Speed-metre configurations of GW interferometers are known to provide a significant improvement of quantum noise limited sensitivity at low frequencies because by suppression of quantum back-action noise using QND measurement of speed [28,32]. This advantage increases the signal-to-noise ratio (SNR) of speedmetre-based GW detectors for compact binary coalescences by at least two orders of magnitude if compared to the equivalent Michelson interferometer in the quantum-noise-limited case [33]. Zero-area Sagnac interferometer is one of the possible ways to realise the GWD based on speed-metre principle.…”

Research on Telescope TTL Coupling Noise in Intersatellite Laser Interferometry

“…When gravitational waves pass, the distance between the test masses will change. This distance change will be read by the laser interferometry system to invert the gravitational wave signal [1,2].…”

Comprehensive characterization of a general composite waveplate by spectroscopic Mueller matrix polarimetry

“…Waveplates made of birefringent materials are basic polarization elements and widely used in optical systems, such as ellipsometry/polarimetry [1,2], interferometry [3,4], tomography [5], cryptography [6] and laser systems [7], to control and manipulate the polarization states of a polarized light. A composite waveplate (CW) consisting of multiple single waveplates can be specially designed and applied as a linear retarder [8], an optical rotator (namely a circular retarder) [9], an elliptical retarder [2], or an elliptical polarizer [10] in the systems.…”