As the sensitivities of LIGO, Virgo and KAGRA detectors improve, calibration of the interferometers (ITFs) output is becoming more and more important and may impact scientific results. For the observing run O3, Virgo used for the first time photon calibrators (PCals) to calibrate the ITF, using radiation pressure of a modulated auxiliary laser beam impinging on the Advanced Virgo end mirrors. Those optical devices, also used in LIGO, are now the calibration reference for the global gravitational wave detectors network. The intercalibration of LIGO and Virgo PCals, based on the same absolute reference called the gold standard, has allowed to remove a systematic bias of 3.92% that would have been present in Virgo calibration using the PCal. The uncertainty budget on the PCal-induced displacement of the end mirrors [North end (NE) and West end (WE)] of Advanced Virgo has been estimated to be 1.36% for O3a and 1.40% on NE PCal (resp. 1.74% on WE PCal) for O3b. This uncertainty is the limiting one for the global calibration of Advanced Virgo. It is expected to be reduced below ∼1% for the next observing runs.

随着LIGO，处女座和KAGRA检测器的灵敏度提高，干涉仪（ITF）输出的校准变得越来越重要，并且可能会影响科学结果。对于O3观测，处女座首次使用光子校准器（PCal）来校准ITF​​，它使用的是入射在Advanced Virgo端镜上的调制辅助激光束的辐射压力。这些光学设备（也用在LIGO中）现在成为全球重力波探测器网络的校准参考。LIGO和Virgo PCals的相互校准，基于相同的绝对值称为黄金标准的参考文献已消除了使用PCal在处女座校准中可能存在的3.92％的系统偏差。据估计，高级处女座PCal引起的后视镜[北端（NE）和西端（WE）]位移的不确定性预算为O3a为1.36％，NE PCal为1.40％（分别为1.74％ WE PCal）用于O3b。这种不确定性是高级处女座全球校准的局限性。在下一次观察中，预计会降低到〜1％以下。