282 research outputs found
Optical detector topology for third-generation gravitational wave observatories
No full textThe third generation of gravitational wave observatories, with the aim of providing 100 times better sensitivity than currently operating interferometers, is expected to establish the evolving field of gravitational wave astronomy. A key element, required to achieve this ambitious sensitivity goal, is the exploration of new interferometer geometries, topologies and configurations. In this article we review the current status of the ongoing design work for third-generation gravitational wave observatories. The main focus is the evaluation of the detector geometry and detector topology. In addition we discuss some promising detector configurations and potential noise reduction schemes
Beam shaping
No full textIntroduction In this chapter we review recent research on using alternative beam shapes for reducing thermal noise and other thermal effects in mirrors. High-precision laser interferometry experiments typically make use of the fundamental Gaussian beam, which can be generated with the great spatial stability that is important for achieving low-noise signal readouts. However, the Gaussian beam might not be the optimal choice for all high-precision measurements. The idea of using an alternative beam geometry, specifically a flat-top intensity profile, to reduce mirror thermal noise in optical cavities was discussed first by Kip Thorne and his research group at Caltech in 2000 (Thorne et al., 2000). Since then several groups have made progress in taking this idea closer to reality. Despite these efforts, no highprecision interferometric measurement actually showing lower thermal noise has so far been undertaken with alternative beam shapes. Alternative beam shapes improve thermal noise, and specifically coating thermal noise, by effectively increasing the wm parameter of Equation 4.9 and subsequent related equations. Straightforward increasing of the beam width wm of a Gaussian beam will work up to a point, but the optical loss from light spilling over the mirror edge generally will be unacceptable at some level. Thus, with purely Gaussian beams, there is a tradeoff between lower thermal noise (larger wm) and lower shot noise (higher optical power, thus smaller wm). Using beam shapes other than Gaussian is a way to change this tradeoff, because alternative beam shapes can be effectively larger while keeping the light mostly contained on the face of the optic.</p
The next generation of interferometry: Multi frequency optical modelling, control concepts and implementation
No full text[no abstract
The Virgo Interferometer for Gravitational Wave Detection
No full textThe Virgo interferometer for gravitational wave detection is described. During the commissioning phase that followed the first scientific data taking run an unprecedented sensitivity was obtained in the range 10-60 Hz. Since then an upgrade program has begun, with the aim of increasing the sensitivity, mainly through the introduction of fused silica wires to suspend mirrors and by increasing the Finesse of the Fabry-Perot cavities. Plans until the shutdown for the construction of the Advanced Virgo detector are given as well as the status of the upgrade
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