This is report about in-air (GPT) optics installation.
- We brought five QPD mechanical bases from center area.
- After BRT part was installed and aligned, we started to install GPT part (in-air part).
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We found that damping of TMS-VIS was not necessary for GPT installation
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Following the design, we installed the beginning part of the green light path; two periscope mirrors, two steering mirrors, and one lenses.
- First periscope mirror (GPM1): TFM-50C080532 (Opto-Sigma) [1st figure]
- Second periscope mirror (GPM2): TFM-50C080532 (Opto-Sigma) [2nd figure]
- First steering mirror (GST1): TFM-50C080532 (Opto-Sigma) [3rd figure]
- Second steering mirror (GST2): TFM-50C080532 (Opto-Sigma) [4th figure]
- First lens (GLNS1, f=500): LA1380-A-ML (Thorlabs) [5th figure]
- At first, all mirrors were installed. Then the lens was installed not to change beam position.
- The lens position, i.e. beam profile, was not tuned since the tuning was not so effective without arm cavity locked.
- In the end of today's work, we installed DC PD (PDA100A2, Thorlabs) after GST2 temporarily. The gain was set to 0 dB. [6th figure]
- After all, GPT part looks like the last attached figure. [7th figure]
