Exploration of sensing function in LIGO O5 with balanced homodyne detection for calibration systematic error estimation

Yuki Inoue^1,3,2*, You-Ru Lee¹, Avani Patel¹, Jeff Kissel⁴

¹Department of Physics, National Central University, Taoyuan, Taiwan
²Institute of Physics, Academia Sinica, Taipei, Taiwan
³Center for High Energy and High field, National Central University, Taoyuan, Taiwan
⁴LIGO Hanford Observatory, WA, USA

* Presenter:Yuki Inoue, email:iyuki@ncu.edu.tw

In the observation of gravitational waves, calibration is an essential process for determining systematic errors in measurements. The model of interferometer can be broadly divided into the Sensing Function and Actuation Function. The Sensing Function relies heavily on the operational method as it represents the response of interferometer. In previous studies, a sensing model incorporating cavity pole, anti-spring effect, and time delay is used and well modeled. However, in O5, the response function of sensing function is dramatically changed due to the combination of significant homodyne and Detuning angles is utilized in conjunction with squeezing. To keep the systematic error, the development of modeling method for new sensing function is necessary. To solve this issue, we employ the simulation software finesse3 and analytical method. In this talk, we will discuss the progress of modeling of quantum effect with homodyne detection and impact on the gravitational wave systematic error estimation.

Keywords: Gravitational wave, Quantum optics, Calibration, Systematic error