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Entry   Coupling efficiency improvement, posted by Xinyi Lu at Optical room about lasers and optics Coupling_efficiency_0110.jpgdamaged_spot_on_M1.png
    Reply   Coupling efficiency improvement, posted by Xinyi Lu at Optical room about lasers and optics coupling_efficiency.jpgcavity_locking.jpg
Message ID: 180     Entry time: Mon Jan 15 19:19:00 2024     In reply to: 179
 Author: Xinyi Lu 
 Status: Fixed 
 Type: info 
 Category: lasers and optics 
 Location: Optical room 
 Title: Coupling efficiency improvement 

- We got 30% coupling efficiency by installing a set of telescopes, adjusting the polarization and optimizing the alignment. The diameter of the cavity mode is about 2.1mm.
- Ronic and I successfully locked the optical cavity. Tomorrow we will test the FSR and finesse.

Xinyi Lu wrote:

- Recently we have focused on improving the coupling efficiency. Without the telescope, the original coupling efficiency was less than 3%.
- I measured the parameters of the incident CW laser using both a HASO wavefront sensor and a CCD. I designed and installed the telescope, but the coupling efficiency still did not improve.
- After discussing with Aurélien and Ronic, it was decided to replace the M1 because the original M1 has a damaged spot in the center to the left. The damaged spot may be causing the coupling efficiency to be too low.
- Today, I replaced the M1 and realigned the cavity. Fortunately, the coupling efficiency has improved.
- We'll continue to optimize the alignment, improve the coupling, and carry out tests on the cavity.

 

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Attachment 2: cavity_locking.jpg  3.264 MB  | Show | Show all
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