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Entry   Cavity Alighnment , posted by Manar Amer at ThomX igloo about lasers and optics | detectors and electronics 9x
    Reply   Cavity Alighnment , posted by Manar Amer at ThomX igloo about lasers and optics | vacuum | detectors and electronics 20230404_P4_Transmission.jpg20230404_vacuum_level.jpg
       Reply   CW FP Cavit lock , posted by Manar Amer at ThomX igloo about lasers and optics | detectors and electronics 20230406_setup.jpg20230406_transmission_S2-P4.jpg20230406_Cavity_Lock.jpg
          Reply   CW FP Cavit lock , posted by Manar Amer at ThomX igloo about lasers and optics | detectors and electronics 20230407_103103-2.jpg
             Reply   FP Finesse measurement using CW, posted by Manar Amer at ThomX igloo about lasers and optics | detectors and electronics 20230411_first_Finesse_reading.JPG20230411_second_Finesse_reading.JPG20230411_Beam_Profile_position_differance_when_changing_FSR.JPG
Message ID: 205     Entry time: Fri Apr 7 00:26:11 2023     In reply to: 204     Reply to this: 206
 Author: Manar Amer 
 Status: Fixed 
 Type: report 
 Category: lasers and optics | detectors and electronics 
 Location: ThomX igloo 
 Title: CW FP Cavit lock  

Yesterday morning we locked the cavity on a strange mode in the cavity (we call it mode, but not sure what it is ??)

we also managed to lock on a higher order mode 02

we get an estimated 30% coupling (expected value), and note that we have not installed a telescope yet.

 

Manar Amer wrote:

Today, we prepared lenses for a telescope for the CW laser injection into the cavity, yet to be installed

Image of the transmission at P4 attached, an estimation of the beam size of the mode see is ~ 5.5 mm 

The vacuum in the 2 optical cavities is decreasing but slowly. today it is 2.6 - 2.4 * 10^-7 mbar

Manar Amer wrote:

Last week, with Ronic and Victor we aligned the cavity using CW laser (Koheras)

  • we have also installed 4 mirrors in the cavity with the best theoretical qualities (serial number and images included)
    • The Plan ULE mirror P4 thickness was not compatible with the piezoelectric mount. We had to install a metal spacer behind the mirror to be able to fix it. the metal spacers in from ThorLabs made from INOX, It is 1 inch diameter (25.4 mm), we drilled a hole in the middle of 15 mm in the Workshop in bat 200. Then cleaned it using an ultrasound bath in pure water, using a small Ultrasound bath machine in Maverics platform Vide and Surfaces next to ThomX eglo.
    •  
    • This gives some difficulties in imaging the transmission at P4. To help with the imaging, we used the plastic #D printed irises that Yann made long time ago
    • we took images of the mode inside the cavity at P4 transmission.

 

  • We also observed some oxidization on the metal bars of the controllers, more on the side of S2 and P4. we are yet to test the motion of the motors in the z-axis.
  • Friday evening we closed the windows using a new copper rings (last one we have, Ronic placed a new order).
  • The pump was turned on by Bruno and Eric yesterday afternoon. The current vacuum level is 6-7*10^-6 mbar

the pre and the turbo pimps are on so still too noisy to work, we have access all day tomorrow.

 

 

 

 

 

Attachment 1: 20230406_setup.jpg  122 kB  | Hide | Hide all | Show all
20230406_setup.jpg
Attachment 2: 20230406_transmission_S2-P4.jpg  193 kB  | Hide | Hide all | Show all
20230406_transmission_S2-P4.jpg
Attachment 3: 20230406_Cavity_Lock.jpg  233 kB  | Show | Hide all | Show all
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