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 |
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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optical table cleaning, posted by Ronic Chiche at Optical room about utilities
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this morning with Alice and Daniele, we removed all the optics elements and equipments from the SBOX optical table and started to clean it.
the dust meter count 0 on all particle sizes after the cleaning.
we observed a small part of the SBOX which seems to be oxydised (see picture). |
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optical table cleaning, posted by Ronic Chiche at Optical room about utilities
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this afternoon, we checked the dust meter which is at 0 for 1 and 5µm dust particles but ~ 2000-3000 for 0.3µm particles.
we opened the two top panels to let the air flow clean the inside of the vessel.
we observed some other minor oxydised regions (than the one taken in picture) on the external parts of the inox panels but at first sight, 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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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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optical table cleaning, posted by Ronic Chiche at Optical room about utilities
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now, it seems the table is clean enough (dust meter counts 0 particles) to install a 2 mirrors FP-cavity.
Ronic
Chiche wrote:
this afternoon, we checked the dust meter which is at 0 for 1 and |
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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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first attempt to lock, posted by Ronic Chiche at Optical room about mechanics | lasers and optics | detectors and electronics
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With Alice, we installed the EOWaves oscillator to be locked on the FP-cavity (T1 ~ 2500ppm, T2 ~ 10ppm => F ~ 2500)
FSR = 216MHz => LW = 86kHz.
We installed the PDH box, and we got some error signal, but the shape of the transmission signal and error signal is a bit strange... |
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Installation of the avalanche photodiode, posted by Ronic Chiche at Optical room about lasers and optics | detectors and electronics
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After installing the 2nd EOM, we had some trouble to be able to lock again.
One possible reason was the very low signal level in transmission, which is important to trigger the locking system (and stop it).
See the Alice post for details, but we were able to measure only once the Finesse of the cavity at around 2600. |
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Transmission Measurements for the Mirrors. , posted by Manar Amer at Optical room about lasers and optics 6x
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Thursday 10 December 2020: First Test Measurement - Inside Box
The transmission ( T ) for the mirrors of SBOX
and ThomX was measured over a range from the center of the mirror up to 5mm.
The first setup was initially done while the
mirrorr is installed inside the metal box, when measuring T we observe that there is an erregular change in the power measured as we move azay from |
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OEwaves CW Laser - Phase Noise , posted by Manar Amer at Optical room about lasers and optics | detectors and electronics
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We started measuring the phase noise on the OEwaves CW laser.
Class 3b
wavelength 1.5 um
The
procedure is done using self coupling of the laser
splitter 50%-50%\
delay line 100 m
all fibers are PM type
(polarity maintained)
Photodetector is "lab buddy", very fast diode.
Note: différance from schematic (we did not |
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OEwaves CW Laser - Phase Noise , posted by Manar Amer at Optical room about lasers and optics | detectors and electronics
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a correction on the wavelength of the laser it is 1030 um
Manar
Amer wrote:
We started measuring the phase noise on the OEwaves CW laser.
Class |
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OEwaves CW Laser - Phase Noise , posted by Manar Amer at Optical room about lasers and optics | detectors and electronics
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correction on unit 1030 nm
Manar
Amer wrote:
a correction on the wavelength of the laser it is 1030 um |
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Dust Cleaning of SBox, posted by Manar Amer at Optical room about utilities
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An Initial cleaning of the KBoX outside was done, All the optics and mechanics placed that were on the table were removed.
Only the old Mitylaser amplifier remains on the table.
Since we will be using the ThomX Celia amplifier, we will remove it and place it in a secure location (to be decided). |
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Dust Cleaning of SBox, posted by Manar Amer at Optical room about utilities
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The cleaning was done twice with half an hour interval between the two times
reading on the dust meter was taken after each time, and it was zero averaged over a 10-min
Manar |
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Mightylaser Amplifier , posted by Manar Amer at Optical room about lasers and optics | cabling
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Migthylaser amplifier has been moved from the SBox table to the PLIC table.
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Spincoater - Mirrror cleaning , posted by Manar Amer at Optical room about utilities
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In preparation for cleaning the mirrors.
The spincoater has been moved with its bump into the sas of the SBox.
The pure water used will be provided by Alice, as the previous source in the workshop is not available. |
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Dust Cleaning of SBox, posted by Manar Amer at Optical room about mechanics | lasers and optics | utilities 6x
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The inside of the cavity was cleaned today. It was very dirty and had big dust particles and fibers inside.
Cleaning was done for everything; wall, floor, fixed mounts, wires (still have some dust difficult to remove), edges.
The dust meter average was measured outside the cavity (2471 p/m3 av 6 min) and inside after cleaning (1424 p/m3 av 10 min). |
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Dust Cleaning of SBox, posted by Manar Amer at Optical room about mechanics | lasers and optics | utilities
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After an overnight where the cavity box was left open, a measurement of the Dust meter was taken:
Outside on the optical table on direct air flux (1701 p/m3 Av 10 min) and
Inside the cavity box (998 p/m3 Av 10 min) |
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Clean Airflow Dust measurements, posted by Manar Amer at Optical room about detectors and electronics | utilities
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The dust meter cap was cleaned using Alcohol, and using the filter white cap the dust count was (0 Av. 10 min)
After the dust counter was hand held in direct airflow, it counted (1581 p/m3 Av. 2 min).
I tested the count also in the SAS, and it counted twice the amount ~ 4500 p/m3 |