Overview of Calibration Systems in KAGRA Observatory

Hsiang-Yu Huang on behalf of the KAGRA collaboration^1,2*

¹Department of Physics, National Taiwan Normal University, Taipei, Taiwan
²Institute of Physics, Academia Sinica, Taipei, Taiwan

* Presenter:Hsiang-Yu Huang on behalf of the KAGRA collaboration, email:siangyu1016@gate.sinica.edu.tw

The study of Gravitational wave (GW) astronomy captures intense interest after the first signal detection from binary black hole merger in 2015. KAGRA, a gravitational wave detector located in Japan, performed a joint observation with GEO 600 in April 2020, called O3GK.
Calibration and system characterization play important roles in accurate GW signal reconstruction from interferometer response. KAGRA have built two calibration instruments for precise calibration of the interferometer -- the photon calibrator (PCal) is the main calibrator in O3GK, and the gravity field calibrator (GCal) is for upgrades towards next LIGO-VIRGO observation (O4).
Overview of the design concept, hardware construction and performance will be presented. This would complement a poster contribution which discusses procedures and details of analysis of calibration instruments and systematic error.

Keywords: KAGRA, Gravitational Wave , Calibration, Photon calibrator, Gravity field calibrator