Alignment procedure, posted by Ronic Chiche at Optical room about mechanics | lasers and optics 
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Picture of the installed mirrors inside the FP cavity.
To install an Iris instead of a mirror :
One has to remove manually the orange nuts and replace the mirror mount with the Iris mount. |
Documentation about mechanics on Atrium, posted by Ronic Chiche at ThomX igloo about mechanics
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https://atrium.in2p3.fr/0dded51a-1cb0-43e6-ae0d-626cd5db7078
a lot of schematics regarding the FP cavity are stored by the mechanic group on the Atrium repository. |
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FP cavity mode axis change and Finesse measurement, posted by Ronic Chiche at ThomX igloo about lasers and optics
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this morning with Manar, we did a cavity mode axis change.
we checked the cavity mode centroid position on the beam profiler (placed behind P4) and changed it by roughly 1mm on the X-axis and by 500µm
on the Y-axis. |
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First hands on the Alphanov amplifier & software, posted by Ronic Chiche at ThomX igloo about lasers and optics
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Aurélien, Manar, and I spent more than 2h trying to start the software communicating with the Alphanov amplifier controller.
each time, we had a problem with the software, asking to switch OFF and ON the controller before being able to switch the amplifier diodes ON.
we switched OFF and ON many times without any success. |
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First hands on the Alphanov amplifier & software, posted by Ronic Chiche at ThomX igloo about lasers and optics
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Additional information related to the injected power into the amplifier fibers.
power = 4.45 mW (as shown from the software)
the minimum to inject into amplifier is 2 mW |
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Alphanov amplifier power measurement, posted by Ronic Chiche at ThomX igloo about lasers and optics
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This morning, with Manar and Aurélien, we measure the power directly at the output of the Alphanov amplifier with the 2 compressors CVBG
(seeding laser at Frep = 133MHz)
(we had to remove the base plate where the deflector mirrors were mounted to put the large powermeter). |
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Alphanov amplifier power measurement, posted by Ronic Chiche at ThomX igloo about lasers and optics
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answers from Guillaume:
- the chiller temperature has to be set to 25°C
- the power measured with the software can change a little from what Alphanov measured with their laser. |
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First hands on the Alphanov amplifier & software, posted by Ronic Chiche at ThomX igloo about lasers and optics
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Software Works well and is operational.
Just closing the log series!!!
Ronic |
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Alphanov amplifier compressor's CVBG thermal images, posted by Ronic Chiche at ThomX igloo about lasers and optics
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last Friday with Manar, we took some thermal images of the Alpnavov compressor box.
I post a small document to summarize some points :
- the 2 mirrors used to make the CVBG injection are polarized thin-film mirrors... thus sensitive to the beam polarization. |
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Alphanov amplifier compressor's CVBG thermal images, posted by Ronic Chiche at ThomX igloo about lasers and optics
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last Friday with Manar, we took some thermal images of the Alpnavov compressor box.
I post a small document to summarize some points :
- the 2 mirrors used to make the CVBG injection are polarized thin-film mirrors... thus sensitive to the beam polarization. |
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Vessels vacuum at ambiant pressure, posted by Ronic Chiche at ThomX igloo about vacuum
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Last Friday and this morning, with Bruno, we close the ring/cavity valves and put some dry air in the two vessels through a filter to avoid turbulences.
Now, the two vessels are at ambient pressure and ready for opening (to remove the mirrors).
One can let the ambient pressure in the vessels as long as we want, the ring/cavity valves have been chosen to be compatible with the high vacuum |
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mirrors removing, posted by Ronic Chiche at ThomX igloo about lasers and optics
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This morning with Viktor, we opened the 2 vessels and removed the 4 FP-cavity mirrors.
all the mirrors have been put in plastic boxes with labels to indicate which mirror it is,
and with all the HR coatings face down. |
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33MHz laser SN2439 back to Orsay, posted by Ronic Chiche at Optical room about lasers and optics
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On the 8th of July, the SN2439 33MHz laser was returned from NKT to our lab, being repaired.
it stayed all the weekend to warm up in the optical room and has been turned on on Monday.
the mode-locking was not working (28mW output power and a CW line for the optical spectrum), thus I "kicked" the laser with 100µm |
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33MHz laser SN2439 back to Orsay, posted by Ronic Chiche at Optical room about lasers and optics
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This morning, with Aurélien and Daniele, we did the swap between the 33MHz and 133MHz oscillators.
now, the 33MHz oscillator is on ThomX inside the casemate.
it has been restarted and some laser is going out. |
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33MHz laser SN2439 back to Orsay, posted by Ronic Chiche at Optical room about lasers and optics
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Yesterday with Aurélien, we try to make the laser modelock using the Smaract translation stages embedded inside the laser head.
unfortunately, we got some errors when we try to do the "calibration" and "reference" of both Smaract stages !
we contacted by email M. Nicoul to help us on this topic |
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33MHz laser SN2439 back to Orsay, posted by Ronic Chiche at Optical room about lasers and optics
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Today, we used an "ELI-NP" Smaract controller made with these 2 references :
MCS-3CC-ETH-TAB (SN 2271) => main controller
MCS-3S-EP-SDS15-TAB (SN 2472) => sensor module |
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33MHz laser SN2439 back to Orsay, posted by Ronic Chiche at Optical room about lasers and optics
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Yesterday, we put back the 33MHz oscillator into the casemate with the new Smaract controller.
after switching ON the laser controller, we saw some power at the output but we have to check if the laser is modelock or not.
Ronic |
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33MHz laser SN2439 back to Orsay, posted by Ronic Chiche at Optical room about lasers and optics
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Today, we succeded to make the laser modelock.
the ouptut power is above 35mW (the powermeter was saturated)
here is a screenshot of the signal on the scope. |
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Strecher and fiber injection alignment, posted by Ronic Chiche at ThomX igloo about lasers and optics
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Today, after laser was modelocked, we checked the power inside the fiber coming from the Alphanov Strecher box.
it was almost zero, at the nW level.
after doing some very rough alignment, we clearly saw some power (with the powermeter) correlated with the position of mirrors, when turning |
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Strecher and fiber injection alignment, posted by Ronic Chiche at ThomX igloo about lasers and optics
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This morning with Viktor, we started the alignment of the CVBG and fiber.
we did a better alignment of the 2-pass CVBG.
we are able to the see a spot after PBS (after the 2 CVBG pass) which means the alignment is OK even if it can be improved. |