Simulation meeting 2022 Jun 2 15:00
Naoki Koyama, June Gyu Park, Yoichi Aso, Kentaro Somiya, Matteo Leonardi, Marc Eisenmann, Haoyu Wang
Updates from Projects
- Birefringence simulation
We performed a very preliminary alignment sensing simulation for birefringence with single arm cavity slide.
- Birefringence does not affect the operating point of the PDH error signal.
- The birefringence in ITM will add distortion to the s-pol beam, introducing TEM01 (or TEM10) mode. This will generate an offset to the wavefront sensing error signal even though the cavity is well aligned.
- This offset seems constant if the beam position on the ITM doesn't change. It probably can be compensated by looking at the transmission power of the cavity.
- But when the beam position on the ITM changes, this offset will change. We need more accurate birefringence characterizations for KAGRA ITMs.