Conveners
Technical noise for LF
- Daniel Brown (University of Adelaide)
- Jenne Driggers (Caltech, LIGO Hanford)
One of the main limits of the Quantum Noise Reduction in Gravitational Wave detectors is the optical losses generated by the mismatch between the vacuum squeezed beam and the resonant cavities of the interferometer. In order to correct those aberrations, we need to be able to measure them. For this reason, different efforts have been made to develop wave-front sensing techniques to measure the...
KAGRA is a cryogenic detector using sapphire mirrors as its test masses. The sapphire material was chosen mainly for its high thermal conductivity, low absorption and high transmittance of the 1064 nm laser. However, sapphire has a few disadvantages like birefringence. During the commissioning, we found out the interferometer had unexplained optical losses and beam distortions due to the...
Control noise dominates the low frequency spectrum of gravitational wave detectors. Improving sensors and hence local control will ease requirements for global control and reduce noise reinjected into the detector. Three Homodyne Quadrature Interferometers (HoQIs) were installed at the middle-mass of the beamsplitter triple suspension at AEI-Hannover’s 10m prototype interferometer. HoQIs have...
The Einstein Telescope (ET) is a third-generation gravitational-wave detector, which is expected to be 1000 times more sensitive than current instruments at low frequencies. In this frequency range, detectors have been limited by technical noises. Alignment control is at the frontline of the limiting noises.
The amount of angular control noise chained to the sensitivity depends upon the...
The coupling of environmental magnetic fields is a limiting factor for the lowfrequency sensitivity of future ground-based interferometers. Coupling can occur at various locations, such as actuation magnets of the mirror and optical benches isolation systems. Eddy currents in conductive parts can locally warp magnetic fields and enhance magnetic forces. A major goal for future detectors is to...
