CFBG removed from ThomX CELIA amplifier, posted by Loïc Amoudry at Optical room about lasers and optics
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The CFBG has been removed successfully and the amplifier is closed now.
The soldering machine had a calibration trouble and was sent to the company for review during holidays.
The output power has been checked and is the same as before (tested until 30W ouput power). |
CELIA amplifier installation + chiller, posted by Manar Amer at Optical room about lasers and optics | detectors and electronics | software 
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Amplifier placed next to the pulsed laser on the table under the airflow
The output is in free space with height from the table of about 10 cm, note the injection height into the cavity is between 14 - 15 cm.
a power cable is placed but not plugged. |
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CELIA amplifier installation + chiller, posted by Manar Amer at Optical room about lasers and optics | detectors and electronics | software
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The software to control the CELIA amplifier is on the laptop that was placed in ThomX bunker.
I have placed it in the PLIC room next to the SBox table.
it is called 'Alphanov Control Software' |
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CELIA amplifier installation + chiller, posted by Manar Amer at Optical room about lasers and optics | detectors and electronics | software
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Closing series
Manar
Amer wrote:
The software to control the CELIA amplifier is on the laptop that was |
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CELIA amplifier installation, posted by Manar Amer at Optical room about lasers and optics | detectors and electronics | software
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The amplifier was installed on the optical table next to SBox table.
The CVBG that will be used for stretching before amplification needs cleaning (they are very fragile, 'ask victor for best method')
The software to drive the diodes of the amplifier we have is not the compatible one. |
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CELIA 100W laser amplifier repair , posted by Ronic Chiche at Optical room about lasers and optics
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this morning with Alice, we sent the Menhir 160MHz injected in a fiber (with 6mW at the end of a long fiber) into the laser amplifier, to look for leakage
or damage in the first stages of the amplifier (the amplifier is totally off).
first of all, we checked for light scattering around the laser crate with a sensitive optical card => nothing |
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CELIA 100W laser amplifier repair , posted by Ronic Chiche at Optical room about lasers and optics
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this afternoon, we saw some electric cables badly connected to their power supply.
we fixed it by soldering them together and screwing the result to the power supply.
(see 1st image) |
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CELIA 100W laser amplifier repair , posted by Ronic Chiche at Optical room about lasers and optics
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friday morning, we add a zoom call with Jerome Lhermite about the amplifier repair.
he approximately confirmed the amplifier scheme from the Loic thesis.
he suggested to: |
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Beam size vs D-shape position, posted by Loïc Amoudry at Optical room about lasers and optics
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Measurement done on 18/10/18.
At high power, the shape of the 0.0 mode does not change. The D-shape only generate losses in the cavity. Then the power stored in the cavity
decrease. As with this configuration, the cavity beam size decrease when power increase, the beam size decreased. |
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Beam size vs D-shape position, posted by Loïc Amoudry at Optical room about lasers and optics
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Matlab code for size vs position and power :
clear all
close all |
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Beam size behind M2, posted by Ronic Chiche at Optical room about lasers and optics
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Beam diameter behind M2 :
- 2nd stage @ 6A - 1kW inside cavity
sx = 2120 µm |
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Beam size behind M2, posted by Ronic Chiche at Optical room about lasers and optics
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the telescope matchs the cold cavity beam, so it is normal to have a power decrease on the transmission photodiode when the cavity is heating at high
power.
we can try to adjust the telescope by moving lens, one by one, to increase the cavity power. |
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Beam size behind M2, posted by Ronic Chiche at Optical room about lasers and optics
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Yesterday, we tried to better adapt positions of the telescope lenses, dynamically, during the lock, to improve the matching between input beam and cavity
mode.
it is a difficult task because it is quite sensitive to the alignment. we need to realign very often... and it is a long process. |
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Amplifier power and mirror transmission, posted by Xinyi Lu at Optical room about lasers and optics
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Today, Ronic, Daniele, Aurélien and I measured the amplifier power and mirror transmission.
Current (A)
0 (2rd stage)
1
2
3
4
5
6
7
7.5
8
Power
(W)
1
1.8
11.8
23.5
35.5
47
57.5
66.9
70.7
74.9
For |
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Amplifier output Beam Profile, posted by Manar Amer at Optical room about lasers and optics
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In preparation to measure the output beam profile from the amplifier at high power, I have placed two wedge mirrors just before the beam dump to be able
to extract the beam.
One of the wedges was taken from ThomX bunker, also the HR and AR mirrors were taken to plic room in case we might need them |
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Amplifier output Beam Profile, posted by Manar Amer at Optical room about lasers and optics
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Beam divergence after amplifier 4.46 mrad
Manar |
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Amplified laser injection, posted by Xinyi Lu at Optical room about lasers and optics
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In the last two days, Ronic and I connected the amplifier and locked the cavity.
- We installed an iris on the output to remove a part of the pump.
- We turned on the second stage of the amplifier. When locking, the injected power is 220 mW and the transmitted power after M2 is 26 uW. |
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Alignment of a 2-mirror FP cavity, posted by Ronic Chiche at Optical room about mechanics | lasers and optics
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today with Alice,
- we measured the height of the SBOX windows center : 140mm from the optical table.
- we set the laser fiber colimator exactly at this height. |
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Alignment / Table setup , posted by Manar Amer at Optical room about lasers and optics | detectors and electronics | software
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The current setup of the optical table attached.
The cavity is aligned and the lock of the fundamental mode has been attempted, but the mode is drifting too quickly to be able to follow.
I have placed the cavity under vacuum for a better stability. |
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Alignment / Table setup , posted by Manar Amer at Optical room about lasers and optics | detectors and electronics | software
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closing series
Manar
Amer wrote:
The current setup of the optical table attached. |