Expanding the Reach of Quantum Enhanced Gravitational-Wave Detectors

TheAdvancedLIGOdetectorsarethemostprecisedisplacementsensorsevermade,operating at the cutting edge of quantum noise limited sensitivity. The introduction of non-classical squeezed states to reduce quantum shot noise during the third gravitational wave observing run O3 ushered in the era of quantum-e...

Full description

Bibliographic Details
Main Author: Ganapathy, Dhruva
Other Authors: Evans, Matthew
Format: Thesis
Published: Massachusetts Institute of Technology 2024
Online Access:https://hdl.handle.net/1721.1/156780
_version_ 1826207910678495232
author Ganapathy, Dhruva
author2 Evans, Matthew
author_facet Evans, Matthew
Ganapathy, Dhruva
author_sort Ganapathy, Dhruva
collection MIT
description TheAdvancedLIGOdetectorsarethemostprecisedisplacementsensorsevermade,operating at the cutting edge of quantum noise limited sensitivity. The introduction of non-classical squeezed states to reduce quantum shot noise during the third gravitational wave observing run O3 ushered in the era of quantum-enhanced gravitational wave interferometry. This was, however, accompanied by an increase in measurement back-action, in the form of quantum radiation pressure noise which degraded detector sensitivity at low frequencies below 100Hz. In the early 2000s, Kimble et. al. [1] proposed the use of optical filter cavities to prepare frequency dependent squeezed states which circumvent measurement back-action by suppressing radiation pressure noise at low frequencies while continuing to reduce shot noise across the rest of the gravitational wave signal band. In this thesis, we explore frequency dependent squeezing for gravitational wave detectors, with an emphasis on optimal filter cavity design, and characterization of squeezing in optical systems. We then describe the commissioning of a 300m filter cavity for the first realization of frequency dependent squeezing in gravitational wave interferometer for the fourth gravitational wave observing run O4. Along with significantly enhancing the astrophysical sensitivity of the LIGO detectors, this is also the latest milestone in several decades of research in quantum noise reduction. We conclude the thesis by extending frequency dependent squeezing to alternate interferometer configurations by studying the feasibility of detuning the signal cavity of the interferometer to enhance sensitivity to kilohertz signals from neutron star post-mergers.
first_indexed 2024-09-23T13:56:53Z
format Thesis
id mit-1721.1/156780
institution Massachusetts Institute of Technology
last_indexed 2024-09-23T13:56:53Z
publishDate 2024
publisher Massachusetts Institute of Technology
record_format dspace
spelling mit-1721.1/1567802024-09-17T03:27:12Z Expanding the Reach of Quantum Enhanced Gravitational-Wave Detectors Ganapathy, Dhruva Evans, Matthew Massachusetts Institute of Technology. Department of Physics TheAdvancedLIGOdetectorsarethemostprecisedisplacementsensorsevermade,operating at the cutting edge of quantum noise limited sensitivity. The introduction of non-classical squeezed states to reduce quantum shot noise during the third gravitational wave observing run O3 ushered in the era of quantum-enhanced gravitational wave interferometry. This was, however, accompanied by an increase in measurement back-action, in the form of quantum radiation pressure noise which degraded detector sensitivity at low frequencies below 100Hz. In the early 2000s, Kimble et. al. [1] proposed the use of optical filter cavities to prepare frequency dependent squeezed states which circumvent measurement back-action by suppressing radiation pressure noise at low frequencies while continuing to reduce shot noise across the rest of the gravitational wave signal band. In this thesis, we explore frequency dependent squeezing for gravitational wave detectors, with an emphasis on optimal filter cavity design, and characterization of squeezing in optical systems. We then describe the commissioning of a 300m filter cavity for the first realization of frequency dependent squeezing in gravitational wave interferometer for the fourth gravitational wave observing run O4. Along with significantly enhancing the astrophysical sensitivity of the LIGO detectors, this is also the latest milestone in several decades of research in quantum noise reduction. We conclude the thesis by extending frequency dependent squeezing to alternate interferometer configurations by studying the feasibility of detuning the signal cavity of the interferometer to enhance sensitivity to kilohertz signals from neutron star post-mergers. Ph.D. 2024-09-16T13:48:42Z 2024-09-16T13:48:42Z 2024-05 2024-08-18T14:25:52.271Z Thesis https://hdl.handle.net/1721.1/156780 In Copyright - Educational Use Permitted Copyright retained by author(s) https://rightsstatements.org/page/InC-EDU/1.0/ application/pdf Massachusetts Institute of Technology
spellingShingle Ganapathy, Dhruva
Expanding the Reach of Quantum Enhanced Gravitational-Wave Detectors
title Expanding the Reach of Quantum Enhanced Gravitational-Wave Detectors
title_full Expanding the Reach of Quantum Enhanced Gravitational-Wave Detectors
title_fullStr Expanding the Reach of Quantum Enhanced Gravitational-Wave Detectors
title_full_unstemmed Expanding the Reach of Quantum Enhanced Gravitational-Wave Detectors
title_short Expanding the Reach of Quantum Enhanced Gravitational-Wave Detectors
title_sort expanding the reach of quantum enhanced gravitational wave detectors
url https://hdl.handle.net/1721.1/156780
work_keys_str_mv AT ganapathydhruva expandingthereachofquantumenhancedgravitationalwavedetectors