Research Report
ICRR Inter-University Research Program 2022
Research Subject:
Filter cavity experiments for the frequency dependent squeezed light for KAGR A
Principal Investigator:
Ray-Kuang Lee (National Tsing Hua University, Taiwan)
Participating Researchers:
Chien-Ming Wu, National Tsing Hua University, Taiwan
Yao-Chin Huang, National Tsing Hua University, Taiwan
Yi-Ru Chen, National Tsing Hua University, Taiwan
Hsun-Chun Wu, National Tsing Hua University, Taiwan
Matteo Leonardi, National Astronomical Observatory of Japan
Eleonora Capocasa, National Astronomical Observatory of Japan
Yu-hang Zhao, National Astronomical Observatory of JapanShinji Miyoki, The University of Tokyo
Summary of Research Result：With ICRR and NAOJ, in this ICRR Inter-University Research Program 2022,
entitled “Filter cavity experiments for the frequency dependent squeezed light for
KAGRA,” we worked with the KAGRA Filter Cavity (KFC) working group. The target
is to implement this FDSQZ to upgrade the sensitivity of KAGRA.
In addition to the bi-weekly telecoms with the working group on the KAGRA FilterCavity, in November 2022 and February 2023, our visits to the KAGRA F2F meetingin Kashiwa and to the 令和 4 年度東京大学宇宙線研共同利用研究成果発表会/Research
Results Presentation Meeting of the ICRR Inter-University Research Program
FY2022 were both supported by this project.
Currently, we take the responsibility for the Interface Optics in the KFC working
group, as well as the OPO design for the squeezer. In addition, we also received theVanguard Project (for 4 years), entitled “Development on the Instrumentations andData Analyses for Advanced Gravitational Wave Detectors,” from the Ministry ofScience and Technology (MOST), Taiwan.
At the same time, we developed about machine-learning (ML) enhanced quantum
state tomography (QST) for squeezed states, as a crucial diagnostic toolbox for theadvanced gravitational wave detectors. Applications on the ML to frequency
dependent squeezing (FDS) is also in progress. As listed below, we reported ourresearch in the annual meeting of the ICRR Inter-University Research Program
FY2022, and published 4 papers with ICRR acknowledged.
•Filter cavity experiments for the frequency dependent squeezed light for
KAGRA, 令和 4 年度東京大学宇宙線研共同利用研究成果発表会/ResearchResults Presentation Meeting of the ICRR Inter-University Research
Program FY2022•

Hsien-Yi Hsieh, Yi-Ru Chen, Hsun-Chung Wu, Hua Li Chen, Jingyu Ning,
Yao-Chin Huang, Chien-Ming Wu, and RKL, "Extract the Degradation
Information in Squeezed States with Machine Learning," Phys. Rev. Lett. 128,073604 (2022).

•

Hsien-Yi Hsieh, Jingyu Ning, Yi-Ru Chen, Hsun-Chung Wu, Hua Li Chen,
Chien-Ming Wu, and RKL, "Direct parameter estimations from machinelearning enhanced quantum state tomography," Special Issue "Quantum
Optimization & Machine Learning"; Symmetry 14, 874(2022).

•Yuhang Zhao, Eleonora Capocasa, Marc Eisenmann, Naoki Aritomi, MichaelPage, Yuefan Guo, Eleonora Polini, Koji Arai, Yoichi Aso, Martin vanBeuzekom, Yao-Chin Huang, RKL, Harald Luck, Osamu Miyakawa, PierrePrat, Ayaka Shoda, Matteo Tacca, Ryutaro Takahashi, Henning Vahlbruch,
Marco Vardaro, Chien-Ming Wu, Matteo Leonardi, Matteo Barsuglia, andRaffaele Flaminio, "Improving the stability of frequency dependent squeezing
with bichromatic control of filter cavity length, alignment, and incident beam
pointing," Phys. Rev. D 105, 082003 (2022).

•Naoki Aritomi, Yuhang Zhao, Eleonora Capocasa, Matteo Leonardi, Marc
Eisenmann, Michael Page, Yuefan Guo, Eleonora Polini, Akihiro Tomura, Koji
Arai, Yoichi Aso, Martin van Beuzekom, Yao-Chin Huang, RKL, Harald Luck,Osamu Miyakawa, Pierre Prat, Ayaka Shoda, Matteo Tacca, Ryutaro
Takahashi, Henning Vahlbruch, Marco Vardaro, Chien-Ming Wu, Matteo
Barsuglia, and Raffaele Flaminio, "Demonstration of length control for a filter
cavity with coherent control sidebands," Phys. Rev. D 106, 102003 (2022).

In papers listed above, we added the supports by “The collaborative research programof the Institute for Cosmic Ray Research (ICRR), the University of Tokyo.” in theAcknowledgement.
No. G002