ORCID Profile
0000-0002-4092-9602
Current Organisation
University of Tokyo
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Publisher: AIP Publishing
Date: 11-2020
DOI: 10.1063/5.0022242
Abstract: This paper reports on the design and characteristics of a compact module integrating an optical displacement sensor and an electromagnetic actuator for use with vibration–isolation systems installed in KAGRA, the 3-km baseline gravitational-wave detector in Japan. In the technical concept, the module belongs to a family tree of similar modules used in other interferometric gravitational-wave detector projects. After the initial test run of KAGRA in 2016, the sensor part, which is a type of slot sensor, was modified by increasing the spacing of the slot from 5 mm to 15 mm to avoid the risk of mechanical interference with the sensor flag. We confirm that the sensor performance is comparable to that of the previous design despite the modification. We also confirm that the sensor noise is consistent with the theoretical noise budget. The noise level is 0.5 nm/Hz1/2 at 1 Hz and 0.1 nm/Hz1/2 at 10 Hz, and the linear range of the sensor is 0.7 mm or more. We measured the response of the actuator to be 1 N/A and also measured the resistances and inductances of coils of the actuators to confirm consistency with theory. Coupling coefficients among the different degrees of freedom were also measured and shown to be negligible, varying little between designs. A potential concern about thermal noise contribution due to eddy current loss is discussed. As of 2020, 42 of the modules are in operation at the site.
Publisher: American Physical Society (APS)
Date: 28-04-2020
Publisher: IOP Publishing
Date: 29-07-2020
Publisher: American Physical Society (APS)
Date: 12-11-2020
Publisher: American Physical Society (APS)
Date: 12-11-2020
Publisher: American Physical Society (APS)
Date: 19-01-2023
Publisher: American Vacuum Society
Date: 03-02-2023
DOI: 10.1116/5.0128487
Abstract: We present a number of approaches, currently in experimental development in our research groups, toward the general problem of macroscopic quantum mechanics, i.e., manifestations of quantum noise and quantum fluctations with macroscopic (engineered and microfabricated by man) mechanical systems. Discussed experiments include a pendulum, a torsion pendulum, a ng-scale phononic-crystal silicon nitride membrane, a μ g-scale quartz resonator, and mg-scale mirrors for optical levitation. We also discuss relevant applications to quantum thermometry with optomechanical systems and the use of squeezed light to probe displacements beyond conventional quantum limits.
Location: United States of America
No related grants have been discovered for Kentaro Komori.