Quantum noise modeling and detector configurations

Quantum noise

Quantum noise, together with thermal noise, is one of the two main fundamental noises limiting detector sensitivity. It originates from a quantum description of the state of light, or more colloquially, from the fact that the photodetection is a photon-counting process described by a counting distribution, e.g., a Poissonian distribution. Quantum noise, if expressed as equivalent GW-strain noise, depends on various parameters of the interferometer (light power inside arm cavities, finesse of arm cavities, optical loss), it greatly depends on the interferometer configuration (signal recycling, speedmeter, broadband vs tuned), and finally can also be mitigated with quantum technologies that prepare the light in favorable states (squeezing). Members of this group have contributed to all of these approaches. A review article summarizing some of the basics can be found here [Review article on squeezed-light application for GW detectors (2019)].

Detector configurations

[EPR entanglement for quantum-noise reduction in GW detectors (2017)]

[Conceptual design and modeling of an atom-interferometer GW detector (2020)]

Decoherence / optical loss

[Effect on higher-order spatial modes on squeezed-vacuum fluctuations (2017)]