Participants : M. Eisenmann, D. Haba, S. Lee, M. Otsuka, K. Somiya, K. Takeshita, R. Watanabe, K. Yamamoto

 * Birefringence measurements at NAOJ: 
new AZTEC samples (30 mm diameter) : birefringence seems good (10**-7 or below) and limited by holder's stress
Currently 3D printing new holders that should remove stress
iLM/LMA sample have larger birefringence
iLM starts to sell sapphire substrates

 * Parametric instabilities : 
Can simulate TEM00 but some issues with HOMs
discussion with Hiro Yamamoto planned

  * Coating measurement at U. Toyama :
NAOJ coating measurement slightly postoned due to He leakage (restart next week)
New actuator/transducer designed (half area of previous one with similar pattern electrodes)

  * new ITMs HCB bonding preparation at U. Toyama :
planned for 2026
currently preparing the cleanroom

  * ASC with birefringence at TiTech : 
computing SN of jitter vs QPD shot-noise
checking with optimized QPDs
4 split PD simulation with finesse on-going 

 * absorption measurement at KASI : 
setting up the PCI