Transmission of Sapphire mirror, posted by Loïc Amoudry at Optical room about lasers and optics 
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| See image. |
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ThomX ring injection kicker noise => USB communication issue with Alphanov amplifier, posted by Ronic Chiche at ThomX igloo about detectors and electronics
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several times already, when the electrons ring injection kicker is running @10Hz, we observed peaks at the same frequency on reflected and transmitted
photodiodes,
at the exact moment when the kicker is activated. we have in addition, USB communication issues with the Alphanov amplifier... the connection is |
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ThomX amplifier M2, posted by Loïc Amoudry at Optical room about lasers and optics
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| The ThomX M2 has been measured between 1.5-1.6 for x and y |
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ThomX Locked with CVBGs, posted by Loïc Amoudry at Optical room about lasers and optics
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ThomX has been locked with a new telescope while using compression CVBGs.
Coupling is ~50-55% and lock is stable.
Power up to ~50kW should follow up soon (stop when HOM are observed). We'll not go over ~100kW to not risk any breakdown due to the |
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Tests of pointing stability of the laser CFP, posted by Daniele Nutarelli at ThomX igloo about lasers and optics
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Last monday with Victor we have cheked the stability of de pointing of the laser FP.
The climatisation was operating since 3 days in satble way. The laser pointing was very stable before to inejct in to the cavity (picture 1)
and also for the reflexion from the cavity (picture 2). |
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Temperature control of the Laser length with the inside Peltier, posted by Ronic Chiche at ThomX igloo about lasers and optics
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bunker temperature @ 22.5°C
today, Sebastien Pitrel improved its python software to manually control the laser peltier. |
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Temperature control of the FP-cavity length, posted by Ronic Chiche at ThomX igloo about mechanics | lasers and optics | detectors and electronics
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as the CFP motors displacements induce a cavity unlock, we try to change the cavity length by changing the temperature of elment of the cavity.
yesterday, we tried to put a "heating cable" borrowed to the vacuum group to change the temperature of one bellows between the FP-cavity
and the electron ring. |
Temperature control of the FP-cavity length, posted by Ronic Chiche at ThomX igloo about mechanics | lasers and optics | detectors and electronics
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several days ago, we installed a heating cable around the output flange (close to the X-hutch) of the FP-cavity vessel.
we are able to heat this cable by applying a DC voltage coming from 2 DC voltage supplies in serie (2 devices with 2x 0-30V / 3A => 0-120V /
3A). |
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Temperature control of the FP-cavity length, posted by Ronic Chiche at ThomX igloo about mechanics | lasers and optics | detectors and electronics
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today, I removed one of the DC voltage supply (as with 30V, we are already able to 30°C on the heating cable).
the remaining DC voltage supply is configured in series (2x30V = 60V max) and is at the IP address : 192.168.1.101
Ronic |
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Temperature control of the FP-cavity length, posted by Ronic Chiche at ThomX igloo about mechanics | lasers and optics | detectors and electronics
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this afternoon, I started the heating cable after the warm-up of the FP-cavity :
14h20 : start to fill 50kW in the cavity
15h : start of the heating cable @10V (2x 5V) (iteration 2300) |
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Temperature control of the FP-cavity length, posted by Ronic Chiche at ThomX igloo about mechanics | lasers and optics | detectors and electronics
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last friday, I locked the cavity and then, switched ON the heating cable after waiting the cavity reaches a steady state in frequency drift : see the
figure.
blue : temperature of the probe on the heating cable |
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Temperature control of the FP-cavity length, posted by Ronic Chiche at ThomX igloo about mechanics | lasers and optics | detectors and electronics
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on last tuesday, I did a long-term measurement of the frequency drift when the heating cable is powered ON at 20V (2x 10V) @ t=0mn.
the freqeuncy drift (between the laser, locked in open loop on the FP-cavity, and the RF reference oscillator) acquisition was made by the National
Instrument software. |
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Temperature control of the FP-cavity length, posted by Ronic Chiche at ThomX igloo about mechanics | lasers and optics | detectors and electronics
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today with Fatematuj, we did a long-term frequency drift measurement between the FP-cavity loaded with 50kW and the RF reference frequency... and without
any other thermal source (no heating cable !)
we had a small lock loss at t ~ 120mn. |
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Telescope for compressors and ThomX, posted by Loïc Amoudry at Optical room about lasers and optics
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CVBGs telescope is done with w ~= 1mm.
ThomX telescope is done with w ~= 2.3mm in x and y.
Newt step is to lock with these short pulses (measured ~2.5ps with FWHM standard deviation interference method). |
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Suite tests stabilité, posted by Ronic Chiche at ThomX igloo about lasers and optics
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We continue to find what gives high freq. perturbation.
The laser starts at 92 KW it is stable and locked to the RF. NO high freq parturbation.... With the machine off. (30 min of lock)
We put now the machine ON (All in warming exept pulsed elements)... => the system is very stable NO delock, NO high freq perturbations. The |
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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. |
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Strecher and fiber injection alignment, posted by Ronic Chiche at ThomX igloo about lasers and optics
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In preparation for tomorrow morning, I did a test with a 45° mount to have a power pickup inside the injection box.
I used the 133MHz laser.
output power measured with the powermeter : 45mW |
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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 Manar, we measured the power at different points:
- direct measurement at the output of the 33MHz laser : 35 mW
inside the injection box : |
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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 Ronic, using a pickup mirror, we measured the power in different locations along the path of the stretcher box
Output power from oscillator : ~35mW
After the isolator : ~ 35 mW |