Beam size and finesse, posted by Loïc Amoudry at Optical room about lasers and optics
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Measurement behind P4 (planar mirror)
Loïc
Amoudry wrote:
FSR initiale : 33.34 MHz (S3 = -825000 et S4 = -825000) |
Beam pulse duration, posted by Ronic Chiche at Optical room about lasers and optics 
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We installed the 2 CVBG for compression after the amplifier.
We used an interferometric technique with a delay line and combining the two paths in a CCD to measure interferences... see interferences.avi video
file |
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Beam pulse duration, posted by Ronic Chiche at Optical room about lasers and optics
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Yesterday, Loic installed a telescope before CVBG's to reduce the spot size on CVBG's and reduced the incident angle 0.5-1° on them (on the
datasheet the specified incident angle is 2.8°).
We used an interferometric technique with a delay line and combining the two paths in a CCD to measure interferences. |
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Beam pulse duration, posted by Ronic Chiche at Optical room about lasers and optics
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Yesterday, Loïc put the CVBG's back to their specified angles.
We used an interferometric technique with a delay line and combining the two paths in a CCD to measure interferences.
After supressing the global shape of the superposed pulses, one measures the amplitude of the remaining fringes (standard deviation) each 50µm |
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Beam pulse duration, posted by Ronic Chiche at Optical room about lasers and optics
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Last Thursday (20th of February), Loïc and Titouan realigned the stretcher CVBG to its nominal angle and they used an interferometric technique
with a delay line and combining the two paths in a CCD to measure interferences.
After supressing the global shape of the superposed pulses, one measures the amplitude of the remaining fringes (standard deviation) each 50µm |
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Basic alignment & alignment motors check, posted by Loïc Amoudry at Optical room about mechanics | lasers and optics
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14/02/19: The 4 motors but Mby control works. Mby motor home does not bring it to its "middle" position but to the end of its range.
Issue circumvented using the higher rights software.
The beam is now going through the cavity windows (from P1 to S2). |
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Amplifier output power , posted by Loïc Amoudry at Optical room about lasers and optics
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The ouput power of the ThomX amplifier has been measured as a function of the 3rd stage pumps current (0A is 1st and 2nd stage turned on).
We measured the total power, the total power without the "donuts" pump signal dumped by an iris and the transmission of a dichroic
mirror (for ref see image). |
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Amplifier output power , posted by Loïc Amoudry at Optical room about lasers and optics
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Loïc
Amoudry wrote:
The ouput power of the ThomX amplifier has been measured as a function |
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Amplifier output power , posted by Loïc Amoudry at Optical room about lasers and optics
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We checked the Dichroic mirror we have : it is a DMSP1000 shortpass dichroic mirror as specified in this post.
The Arrow engraved on the edge of the mirror points on the AR surface !
not on the HR surface... |
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Amplifier mission Bordeaux, posted by Loïc Amoudry at Other about mechanics | lasers and optics
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Voyage Bordeaux au CELIA avec Jérôme LHERMITE (Loïc et Titoutan)
1er jour (34°) :
Mesure du spectre et de la puissance des 4 diodes de pompe 3ème étage jusqu’à ~60W (12A). |
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Amplifier mission Bordeaux, posted by Loïc Amoudry at Other about mechanics | lasers and optics
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M² mesuré à 10W.
M²x = 1.17
M²y = 1.14 |
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Amplifier laser diodes issue, posted by Ronic Chiche at Optical room about lasers and optics
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This is a long time issue for the ThomX amplifier : on the 4 pumping diodes available, the 1st diode has a higher temperature than the others around
40°C (see the picture).
the problem comes from the TEC which is not activated (see diodes parameter files in execel format). the related software windows are shaded. |
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Amplifier Beam Profile over time , posted by Manar Amer at ThomX igloo about lasers and optics | detectors and electronics
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This morning, with Ronic, we opened the compressor box to observe if there is any misalignment of the mounts or the CVBG's
a comparison slide between the Beam Profile over time and measurements we have taken, is included.
we noticed
today that the images need a rotation, and I took the assumption we did not rotate last year and did the rotation of the previous images.
Comparing |
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Amplifier Beam Profile over time , posted by Manar Amer at ThomX igloo about lasers and optics | detectors and electronics 10x
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This morning we took data of the beam profile at 4 different points to see the evolution of
the beam shape
divergence
over distance for all amplification percentages
Data plotted for the distance vs radius for all and divergence in rad is extracted and plotted as a variation of amplification power. |
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Amplifier Beam Profile over time , posted by Manar Amer at ThomX igloo about lasers and optics | detectors and electronics
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Information about today's work is added to logBook !!
Manar
Amer wrote:
This morning we took data of the beam profile at 4 different points |
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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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Alphanov amplifier issue, posted by Ronic Chiche at ThomX igloo about lasers and optics
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on Monday morning 7/11, we tried to restart the Alphanov amplifier which was not turned on since end of april 2022, but it didn't start.
we did a standard "turn ON" procedure :
- check the safety button on the front panel (which has to be released). |
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Alphanov amplifier issue, posted by Ronic Chiche at ThomX igloo about lasers and optics
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I just tested the fuse inside the black ON/OFF switch on the rear panel => it is OK ! :-(
Ronic
Chiche wrote:
on Monday morning 7/11, we tried to restart the Alphanov amplifier |
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Alphanov amplifier issue, posted by Ronic Chiche at ThomX igloo about lasers and optics
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The laser amplifier controller has been sent yesterday and received today by Alphannov.
they should do the assessment quickly...
Ronic |