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ShalikaSingh - 20:09, Thursday 09 February 2023 (3170)Get code to link to this report
IRMC realignment and lock

[Nishino-san, Michael, Shalika]

 

Objective: 1. Realignment of IRMC and lock. 

                   2. ML-AUX1 coupling optimization 

 

Details:

 

IRMC:

1. We were able to realign the main laser to reach the IRMC transmission and reflection port. The power at transmission was 1.7 mW and the reflection was 1.69 mW. 

 

2. The mode matching was 99.2/(99.2+7.2) = 93%. (See Fig 1). This was done with the help of a power meter at the reflected path. 

 

3. The IRMC was able to lock successfully and the power at transmission during the lock was 1.14 mW. The transmissivity of the IRMC was 1.14/1.7*100=67%.

 

PLL:

1. In order to increase the coupling we tried rotating the HWP and QWP. It was found that the QWP and HWP for AUX1 were already at the optimal position, so the previous position has been maintained.

 

Next Step:

1. For PLL: We need to tune the polarization to increase the coupling for AUX2 PLL. 

 

Images attached to this report
3170_20230209120359_irmcmodesreflectedpowermeter.jpg