100W CELIA laser amplifier "Power vs Pump current" curve, posted by Ronic Chiche at Optical room about lasers and optics | detectors and electronics 
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We measured again the 100W CELIA laser amplifier with a pump current until 8A.
as the first current pump of the amplifier has a Peltier issue, we don't exceeded 6A on this stage and we compensated with the 3 other stages.
7A average current is obtained with 6A / 7.3A / 7.3A / 7.4A |
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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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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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Cavity polarization states (Koheras), Finesse of 2 polarization states, posted by Loïc Amoudry at Optical room about lasers and optics
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Measurments of Finesse with the 2 polarization states, let's call them H (higher) and L (lower): 24500 for the H and 23500 for the L.
We checked the polarization states in transmission of the FP cavity after a PBS. The H was stronger in PBS trans and the L stronger in PBS ref.
We measured the power in reflection of the PBS and added a half WP that we aligned with the PBS polarization. Then, to get the maximum power |
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Phase measurement with HASO, posted by Loïc Amoudry at Optical room about lasers and optics
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2 measurement.
First one locked, in transmission of M2 with 2nd stage 0A.Total 89 cm from the big waist (planar mirrors). 2 wedges used.
Second one at input beam with the same power. Datas taken at the same equivalent position than the first one. 3 wedges used. |
Phase measurement with HASO, posted by Loïc Amoudry at Optical room about lasers and optics 8x
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* Loic has to fix the number of files (3) regarding the number of measurements (2)
* splitted Intensity and phase HASO files
* image for each file |
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Phase measurement with HASO, posted by Loïc Amoudry at Optical room about lasers and optics
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with just intensity, the coupling is 98%, and with phase, x direction coupling is 95%, y direction 97%, so the telescope is good.
Loïc
Amoudry wrote:
* Loic has to fix the number of files (3) regarding the number of |
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Polarization optimization, posted by Loïc Amoudry at Optical room about lasers and optics
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Optimization of the polarization has been made the 03/10/18. Checked in reflection of the cavity in reflection&transmission of a PBS, locked and
unlocked. Only with 2nd stage.
Ratio values are reflection of PBS divided by transmission or the opposite. |
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Record power-up, posted by Loïc Amoudry at Optical room about lasers and optics
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Measurement made on 03/10/18 (nothing has been done since there).
Stable power in the cavity of 225 kW.
3rd stage current
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Transmission vs D-shape position at different powe, posted by Loïc Amoudry at Optical room about lasers and optics
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Measurements have been done on 18/10/18.
Datas are on excel file, also matlab file. |
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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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Finesse vs power by difference between main and second resonance, posted by Loïc Amoudry at Optical room about lasers and optics
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Measurements show that ratio decrease versus power. BUT, the second resonance measurement induce lower power in the cavity so the ratio is not directly
true.
Also, simulation of the main/second resonance power by Pierre's simulation has shown ratio ~50, ~47.6 and 43.5 respectively for 0A, 2A and |
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Polarization frequency, posted by Loïc Amoudry at Optical room about lasers and optics
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Check of the frequency of the onefive locked on each polarization of the cavity (tilt a waveplate by 45°).
Frequency repetition rate : 133.335 MHz on spectrum analyzer for both polarization locked. |
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Polarization frequency, posted by Loïc Amoudry at Optical room about lasers and optics
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Measurement on 30/10/18.
Loïc
Amoudry wrote:
Check of the frequency of the onefive locked on each polarization |
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Finesse vs power by difference between main and second resonance, posted by Loïc Amoudry at Optical room about lasers and optics
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Measurement on 24/10/18
Loïc
Amoudry wrote:
Measurements show that ratio decrease versus power. BUT, the second |
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Finesse vs power by difference between main and second resonance, posted by Loïc Amoudry at Optical room about lasers and optics
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Measurement on 25/10/2018
Loïc
Amoudry wrote:
Measurements show that ratio decrease versus power. BUT, the second |
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M1 transmission measurement, posted by Loïc Amoudry at Optical room about lasers and optics
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Center of M1:
I (A)
Input power (mW)
Transmitted
power (mW)
Transmission (ppm)
0
78
0.01477
189
4
16500
3.2
194
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Change of the 3 ULE mirrors by 3 spare ULE mirrors, posted by Loïc Amoudry at Optical room about lasers and optics
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| First finesse measurement 20 266, FSR 133.351 MHz under vacuum |
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M4 transmission measurement, posted by Loïc Amoudry at Optical room about lasers and optics
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The kept transmission for M4 is 2.17 ppm. Which is the value measured after alignement (center of the mirror).
These measurements have been taken before alignement.
I (A)
Input power (mW)
Transmitted |