High power experiments (200kW), posted by Xinyi Lu at Optical room about lasers and optics 
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These days, Ronic and I achieved 200kW inside the cavity and 70% coupling efficiency.
- By optimizing the telescope, the coupling reached 70% with iris fully open and maintained 60%-70% coupling at high power.
- The cavity mode went from 2.2mm,2.5mm (38kW) to finally 2.3mm,2.8mm (200kW) without changing a lot. |
High power experiments (200kW), posted by Xinyi Lu at Optical room about lasers and optics
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all the injection power in the chart have not been measured recently but during the Loic thesis period.
and these old measurements stopped at 5.5A of pump current.... so, the data at "8A" is a pure estimation.
about the last measurement : |
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High power experiments (272kW), posted by Xinyi Lu at Optical room about lasers and optics
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Today, Ronic and I achieved 272kW inside the cavity at 7.5A. The coupling maintained 60%-70%.
Amp current (A)
Injection power (W)
Circulating power (kW)
Gain
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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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High power experiments (500kW), posted by Xinyi Lu at Optical room about lasers and optics
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Last week, we achieved a stable intracavity average power of 500kW, limited by amplifier power. The experimental data are shown in Figure 1.
- We measured the transmitted laser with a power meter in the windows behind M2 and M4 respectively, and the results were consistent, so the
measurements were credible. |
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High power experiments (520kW), posted by Xinyi Lu at Optical room about lasers and optics
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Yesterday, Ronic, Xing, Qili and I achieved a more stable 520kW power at 7.5A (71W injection) by optimizing the alignment and locking parameters. (Figure
1)
- The cavity can be stable locked when airflow is on. At 7.5A, the pump temperature is about 28℃. The chiller temperature didn't |
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High power experiments (550kW), posted by Xinyi Lu at Optical room about lasers and optics
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- Today we moved the position of the D-shaped mirror at 6A. When motor1 (vertical) is 0.2mm away from the spot, the power in the cavity rises from 457kW
to 483kW. Gain=8407 is similar to that at low power (Gain=8511). So the D-shaped mirror lost some of the gain in the previous experiments. At 4A and 5A
we did not move the D-shaped mirror. (Figure 1) |
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Larger beam size & Spectrum, posted by Xinyi Lu at Optical room about lasers and optics
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- We re-measured the gain before moving the mirror. Gain ~9000 was achieved at 3A, but as the power increased, the gain dropped and was difficult to
optimize. In fact, we found that each day the gain was a little higher than the previous day.
Amp current (A)
Injection power (W)
Circulating |
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Different cavity modes & Pulse width, posted by Xinyi Lu at Optical room about lasers and optics
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- Last week, we obtained three curves of the variation of different cavity modes with power (Fig. 1). By comparing the gain for similar cavity mode sizes,
we found that the gain always drops with increasing power.
- We measured the pulse width. The pulse width of the seed laser, after CVBG, amplified at 2A was measured by UPD (rise time < 70ps). Code |
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Different cavity modes & Pulse width, posted by Xinyi Lu at Optical room about lasers and optics
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Additional information:
The pulse duration has been performed in RF on a UPD-70-IR2-P photodiode from Alphalas GmbH by carefully deconvoluting the response function
of the photodiode measured directly with the sub-picosecond laser beam. |
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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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Coupling efficiency improvement, posted by Xinyi Lu at Optical room about lasers and optics
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- These days, Ronic, Fatematuj and I measured the beam parameters of the output of the third-stage amplifier.
- We used 2 wedges and reflection filters to reduce the intensity on the CCD.
- We measured multiple points at pump current of 2 A (output power ~10 W). The waist diameter of the output is w_x = 792.26 |
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Coupling efficiency improvement, posted by Xinyi Lu at Optical room about lasers and optics
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Today, Ronic and I installed the new telescope and locked the cavity.
- We locked at the amplifier current of 1 A and obtained 32% of coupling. (see Figure 1)
- The telescope was designed for a current of 2 A (output power ~10 W). To inject this power, we need to add some filters to devices. |
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Coupling efficiency improvement, posted by Xinyi Lu at Optical room about lasers and optics
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- Today, Ronic and I locked at the amplifier current of 2 A and obtained ~60% coupling after optimizing the CEP (see Figure
1).
- The injected power is 10 W at 2 A. We measured only 14 kW inside the cavity, which corresponds to an effective gain of 1,400 and a full gain |
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Injection at the amplifier current of 2 A, posted by Xinyi Lu at Optical room about lasers and optics
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Today, Ronic and I optimized the locking at the amplifier current of 2 A and obtained ~ 21 kW inside the cavity.
- When all the iris open, the injected power is 10 W and the coupling is ~ 40%, corresponding to an effective gain of 2,100 and
a full gain of 5,250. But the coupling may not be the true value because there is a large spot around the output beam. |
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Polarization issue, posted by Xinyi Lu at Optical room about lasers and optics
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These days, Ronic, Aurélien, Fatematuj and I have been doing some tests on polarization issue, trying to see if it is possible to obtain higher
gain under other polarization conditions.
We installed an additional half-wave plate + PBS + PD at the transmission. By rotating the waveplate of the injection laser, we can compare |
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Polarization issue, posted by Xinyi Lu at Optical room about lasers and optics
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just to add some details :
about the S and P polarization frequency shift:
the PZT scan is 10Vpp at 3.1Hz => the slope is 62 V/s because of the triangle shape of the PZT scan. |
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Polarization issue & 50kW with 22W injection, posted by Xinyi Lu at Optical room about lasers and optics
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Today, Ronic and I lock the cavity on the other polarization and achieved 50kW with 22W injection.
- After we optimize and lock the cavity in vertical polarization, we rotate the waveplate at the transmission to minimize the signal, then rotate
the waveplate at the injection laser to maximize the signal. We lock the cavity in this horizontal polarization and optimize CEP and alignment. |
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100W CELIA laser amplifier "how's to" document, posted by Ronic Chiche at Optical room about lasers and optics | software
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1st version of the document.
if some information is not correct or missing, give any comment by replying to this post. |
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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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Menhir pulsed laser locking, posted by Xinyi Lu at Optical room about lasers and optics
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These days, Ronic, Daniele and I achieved stable cavity locking with the menhir pulsed laser.
- After vacuuming, the current cavity finesse is now about 23,000. The diameter of the cavity mode is w_x=2.2mm, w_y=2.7mm.
- We had to compensate for frequency drift by manually adjusting the cavity length to keep locking. |
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Menhir pulsed laser locking, posted by Xinyi Lu at Optical room about lasers and optics
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Here is a simulation of the relative FP-cavity gain vs the CEP for a Finesse of 23000 and taking into account the Menhir laser optical spectrum and several
CVBG parameters.
I added the commented Matlab code to produce this plot. |
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Menhir pulsed laser locking, posted by Xinyi Lu at Optical room about lasers and optics
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Last week, Ronic and I focused on CEP measurements of the menhir laser.
Measurements without Cavity Locking:
Direct measurement of repetition rate (Frep) with a spectrum analyzer.
Altering the laser pump current from 950mA to 850mA, Frep changed by +28Hz.
Measurement of the variation of carrier-envelope frequency |
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Menhir pulsed laser locking, posted by Xinyi Lu at Optical room about lasers and optics
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here is the code to get this last curve
Xinyi
Lu wrote:
Last week, Ronic and I focused on CEP measurements of |
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Cleaning of Mirrors, posted by Xinyi Lu at Optical room about lasers and optics
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Today Daniele, Ronic and I cleaned the mirrors and locked the cavity. However, the finesse was only 13,000 because of the not clean enough environment
and not pure enough alcohol and water.
We will carefully clean the environment, clean the mirrors again with pure alcohol and water and measure the finesse when I return. If it doesn't |
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Cleaning of Mirrors, posted by Xinyi Lu at Optical room about lasers and optics
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- Today we cleaned the environment and put the spin coater and microscope inside the airflow.
- Tomorrow, Daniele and I will clean the mirrors one by one using pure alcohol and water, and measure the finesse each time. If it does not improve,
we will clean them with plasma. |
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Cleaning of Mirrors, posted by Xinyi Lu at Optical room about lasers and optics
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Today, Daniele and I cleaned mirrors one by one using pure water, alcohol, and the spin coater. Here are the measurements of finesse each time:
1. Initial value: 14,076
2. Clean Mirror 2: 20,606 |
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Cleaning of Mirrors, posted by Xinyi Lu at Optical room about lasers and optics
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- Today, Daniele and I cleaned the cavity inside, recleaned the M2 and M4 and their mounts, optimized the locking, and the finesse is now about
25,000.
- Although it's lower than the expected 30,000-40,000, we decided to move on to the next step. In addition, the mount of M4 is |
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Install new mirrors, posted by Xinyi Lu at Optical room about lasers and optics
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Today, Ronic and I installed the new mirrors and got resonance. We can see the oscillations in this high-finesse case. We haven't carefully
optimized the alignment. Coupling efficiency is about 15% and the cavity can be locked.
Tomorrow we will optimize the alignment and locking, and measure the finesse. |
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Install new mirrors, posted by Xinyi Lu at Optical room about lasers and optics
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- In the last two days, Ronic and I installed new mirrors after cleaning the environment, and locked the cavity.
- We added an AOM to feedback on the high-frequency noise, but the locking condition was still not good enough. We found out that the signal generator
available for this AOM has a long delay time (3 us), which may lead to low feedback bandwidth. So tomorrow we will use another AOM and signal generator |
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Install new mirrors, posted by Xinyi Lu at Optical room about lasers and optics
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- Today, Ronic and I changed the signal generator to a low-noise one (with a delay time of only 0.5 us). Then we moved the D-shaped mirrors, optimized
the alignment and locking. We re-measured the finesse and it is 16,760. It improves but not much.
- Tomorrow, we will clean the environment, open the cavity, and use UV light to see if there is any dust on the surface of the mirrors. |
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Install new mirrors, posted by Xinyi Lu at Optical room about lasers and optics
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Yesterday we checked the mirrors with UV light and there was some dust on the mirrors, especially M2.
Today, Daniele, Ronic and I removed M2 and observed it with a microscope. It was indeed dirty, despite we were careful in installing it before.
After that we cleaned it with alcohol and mirror paper, then with a spin coater and pure water. After cleaning, we observed it again and it was much better |
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FSR and Finesse measurement, posted by Xinyi Lu at Optical room about lasers and optics
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- Today, Ronic and I measured the finesse and FSR after optimizing the locking. FSR was adjusted to 160.27 MHz to match the pulsed laser repetition rate.
The finesse was 3029.
Note: It's now CW laser injected, SBOX's old mirrors. There are lots of dust on the old mirrors without cleaning. |
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Coupling efficiency improvement, posted by Xinyi Lu at Optical room about lasers and optics
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- Recently we have focused on improving the coupling efficiency. Without the telescope, the original coupling efficiency was less than 3%.
- I measured the parameters of the incident CW laser using both a HASO wavefront sensor and a CCD. I designed and installed the telescope, but the
coupling efficiency still did not improve. |
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Coupling efficiency improvement, posted by Xinyi Lu at Optical room about lasers and optics
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- We got 30% coupling efficiency by installing a set of telescopes, adjusting the polarization and optimizing the alignment. The diameter of the cavity
mode is about 2.1mm.
- Ronic and I successfully locked the optical cavity. Tomorrow we will test the FSR and finesse. |
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Mounts installation and cavity alignment, posted by Xinyi Lu at Optical room about lasers and optics
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Over the last two days, Viktor, Ronic and I have started to install the mirror mounts and try to align the cavity.
- We used the Menhir laser @ 160MHz for alignment.
- To make it easier to operate, we removed some lenses and waveplates, and kept only a few necessary reflective mirrors. |
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Mounts installation and cavity alignment, posted by Xinyi Lu at Optical room about lasers and optics
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Over the past few days, Viktor, Ronic and I have continued to align the cavity. We installed 4 mirrors and monitored the transmitted laser with
a CCD and photodiode. By adjusting the motors of the cavity mirror stages and the injector mirrors, we obtained resonances and less symmetric TEM20-like
patterns. Possible reasons for this are a mismatch between the beam sizes of the laser and the cavity mode, and the mounts are installed in rough |
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Mounts installation and cavity alignment, posted by Xinyi Lu at Optical room about lasers and optics
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- Over the last few days, Viktor, Ronic and I have reinstalled the mounts and realigned the cavity with CW laser and old mirrors. By optimizing the injector
mirrors, we got the fundamental mode at the transmission. We measured the beam size in the M2 window with a diameter of 2.5 mm.
- The current coupling efficiency is low. There is a need to increase the coupling in order to lock the cavity and measure FSR and finesse. |
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new setup for the 160MHz Menhir oscillator, posted by Ronic Chiche at Optical room about mechanics | lasers and optics | detectors and electronics | software
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from the begining of the week, Xinyi, Aurélien, Viktor and myself started to install a new setup for the Menhir 160MHz oscillator.
the goal is to rich a record power in the FP-cavity.
- the 160MHz Menhir oscillator has been injected in a fiber. |
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New mirrors batch informations, posted by Ronic Chiche at ThomX igloo about lasers and optics
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the 2 files describe the specfications for the 16 mirrors ordered (4 for ThomX + spare, 4 for SBOX + spare) and the measurements made by the LMA.
I add also a 3rd file in which all the "special' mirrors are referenced. |
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Laser Menhir reinstallation + CVBG + fiber injection, posted by Ronic Chiche at Optical room about lasers and optics
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The lab purchased the Menhir laser @ 216MHz.
it has been sent back to Menhir photonics for inspection, and then is now at lab.
it has been reinstalled to the SBOX setup with injection in a CVBG for pulse stretching before amplification. |
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Damage on mirror surface , posted by Manar Amer at Optical room about lasers and optics
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Following the storage of ~ 50 kW inside the cavity and a sudden drop in transmitted power from the cavity
damage to the mirror surface was suspected.
We broke vacuum and took images of the surface of the 2 mirrors in the cavity, the spherical and the planar mirror |
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Damage on mirror surface , posted by Manar Amer at Optical room about lasers and optics
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Tomorrow will try to shift the injection mirror to avoid hitting the damaged spot.
Manar |
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Damage on mirror surface , posted by Manar Amer at Optical room about lasers and optics
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After discussing, we have decided against shifting the mirror to avoid the time lost.
We changed the injection mirror to a different mirror from Mighty Laser set, Transmission of mirror 80
ppm. (no visible damage at the center of the mirror, only a small scratch on the back) |
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Damage on mirror surface , posted by Manar Amer at Optical room about lasers and optics
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a better image of the damaged spot, image taken with the arrow for the reflective surface facing the other direction (image shows position)
The image of M1 for ThomX reflective surface was taken at min zoom (full image scale 13 mm) and max zoom (full image scale 2 mm) on microscope
The spot appears to be not close to the center of the mirror, at max zoom in the center we do not see the spot it is just out of the image |
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Damage on mirror surface , posted by Manar Amer at Optical room about lasers and optics
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ThomX injection mirror has been cleaned and placed again inside the optical cavity.
This time to avoid the damaged spot I have displaced the mirror mount horizontally to have a distance between center of the beam and the spot
~ 2.5 - 3 mm. |
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M1 ThomX used while shifted from damaged spot , posted by Manar Amer at Optical room about lasers and optics
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Yesterday , we locked the cavity and we see a sign of a high finesse on the transmission signal, but no measurement of Finesse was done.
we have a coupling of ~ 45%, which is a loss of 20% from the previous coupling of 60%
an estimate done by Ronic MATLAB simulation for the coupling drop where we have 200 pp additional losses and gain of 2.6 k we should get a transmission |
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M1 ThomX used while shifted from damaged spot , posted by Manar Amer at Optical room about lasers and optics
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To compare between the 2 images of the cavity mode:
the mode by itself has an integration time of 0.06 ms, position (x, y) = (1142.969, -53.932) um on the beam profiler
the
mode saturated with the spot next to it almost at max intensity has an integration time of 50 ms, position (-3700, -2000) um
comparing |
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M1 ThomX used while shifted from damaged spot , posted by Manar Amer at Optical room about lasers and optics
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On Wednesday 21st , I opened the cavity did an additional 2 mm shift of the injection mirror and put it under vacuum again.
Locked the cavity, and observed the transmitted beam.
The second spot is still visible on the beam profiler , the distance difference between the 2 spots is ~ 5.2 mm (the same as before ) |
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M1 Gamma Factory, posted by Manar Amer at Optical room about lasers and optics
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In the morning, Vacuum broken and rotated M1 ThomX 90 degrees clockwise, locked the cavity in air and we observe a degeneracy close to the fundamental
mode.
In the afternoon, I cleaned M1 from Gamma factory using pure ethanol and pure water with the spincoater |
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M2 ThomX spherical Cleaning , posted by Manar Amer at Optical room about lasers and optics 6x
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Today, M2 Spherical-3 from ThomX that was installed inside the SBox was removed, there was one big dust on the surface of the mirror, mirror was cleaned
using pure ethanol and pure water with spincoater. (images taken with arrow far from us)
M1 from Gamma factory, fixed with the addition of the ring with 3 screws. |
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Power storage In Cavity, posted by Manar Amer at Optical room about lasers and optics
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We start of power output from amplifier of 1W with only the first and second stage on then we start with the third stage power increase,
Note: when changing the current on the third stage 4 diodes, better to do it step by step for each one with a step of ~ 0.5 A
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Power storage In Cavity, posted by Manar Amer at Optical room about lasers and optics
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At transmission power of 42 mW, coupling 60%, we see fundamental mode with a degeneracy
The D-shape motors were moved to a position 2 000 000 steps (in theory they should be the max position)
but no change appeared on the 00 mode or the higher order mode. |
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Power storage In Cavity, posted by Manar Amer at Optical room about lasers and optics
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Power increased in the amplifier
reflective filters added at the transmission point to be able to have signal on the Beam Profiler, Transmission diode and power meter
Amplifier output current |
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Power storage In Cavity, posted by Manar Amer at Optical room about lasers and optics
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at max stage we reached at 2.5 A on the diodes we have
8000 gain , coupling ~ 60% , with power inside the cavity 50 kW
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liPower storage In Cavity, posted by Manar Amer at Optical room about lasers and optics
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After changing the mirror M1 and cleaning the 2 mirrors
They were placed in the cavity box (avoiding touching the mounts to not affect the alignment and placing the mirrors as close to the previous
position) |
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Power storage In Cavity, posted by Manar Amer at Optical room about lasers and optics
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The cavity was locked under vacuum, coupling is approximately < 10%
The lock was relatively easy and the usual sign (oscillations on the transmission tail) of high finesse on the transmission signal was not seen.
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Power storage In Cavity, posted by Manar Amer at Optical room about lasers and optics
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We improved the lock using the alignment, polarization and CEP , the maximum we got was ~ 12% coupling
only the second stage is on !
Decision : this is the maximum we can obtain using the M1 from mighty laser |
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Locking Amplifier with Cavity , posted by Manar Amer at Optical room about lasers and optics
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Today we managed to observe the fundamental mode and stabilize the scan on it until we improved the alignment enough.
We see some coupling, but it is very week < 5% , We improved the alignment and the polarization, but there is still no explanation to why
it is very low. |
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Locking Amplifier with Cavity , posted by Manar Amer at Optical room about lasers and optics
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Today, we played on the CEP but using the I-tune input of the Menhir Laser (+/- 5V maximal range).
unfortunately, one only saw a very weak improvement of the transmission by 10-20%... and the coupling improvement is almost zero.
the best improvement was for the maximal I-tune range (+5V) which maybe means that we could improve more the effect if were able to get a full |
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Locking Amplifier with Cavity , posted by Manar Amer at Optical room about lasers and optics
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We played on the CEP using the USB command "id0=xxxxx" of the Menhir.
we put id0=48650 and we improved A LOT the transmission and coupling (~ 60%)
here is an image of the first attempts to lock... but the locking is quite difficult. |
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Locking Amplifier with Cavity , posted by Manar Amer at Optical room about lasers and optics
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We managed to lock the cavity by adding the AOM , but the lock is still difficult to stabilize.
There is some high frequency compensated by the AOM at ~ 170 kHz (yet to understand from where it comes from)
Manar |
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Locking Amplifier with Cavity , posted by Manar Amer at Optical room about lasers and optics
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We wanted to increase the power of the amplifier to measure the transmission output at M2,
but locking the cavity again was very, very difficult.
We will try again tomorrow. |
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Locking Amplifier with Cavity , posted by Manar Amer at Optical room about lasers and optics
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We locked the cavity, and it is stable using the Transmission,
the high frequency that we thought could have a reason for instability, is due to the high power on the photo diode of the PDH box which can
cause non-linearity effects in the signal. |
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Locking Amplifier with Cavity , posted by Manar Amer at Optical room about lasers and optics
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image of the lock with Coupling of ~ 60%
Manar |
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Locking Amplifier with Cavity , posted by Manar Amer at Optical room about lasers and optics
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Alignment was improved to ~ 1.2 V on the photodiode.
Only the second stage was on with ~ 1 W output from amplifier
we measured the transmission from S2 to be 2.3 mW |
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Telescope / amplifier output, posted by Manar Amer at Optical room about lasers and optics
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The previous Sbox telescope was dismantled and the mechanical components cleaned.
its lenses are still in the mounts, it looks that two of them are spherical and two are cylindrical
2 are -100 mm and 2 are +150 mm, there is also a box containing fused silica lenses that could be used. |
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Telescope / amplifier output, posted by Manar Amer at Optical room about lasers and optics
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Beam divergence was measured using a method called "Focal
Length Divergence
Measurement Method" |
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Telescope / amplifier output, posted by Manar Amer at Optical room about lasers and optics
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I placed a periscope to adjust the high of the beam from the amplifier output from ~ 10 cm from the table to ~ 15 cm
a dichroic mirror placed after it to reject the pump laser, all the mirrors on the path to the cavity were replaced with dielectric mirrors BB01-E03
the length of the path from the amplifier output to the cavity coupling mirror ~ 2 meters |
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Telescope / amplifier output, posted by Manar Amer at Optical room about lasers and optics
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Here is a view of beam propagation in the optical software : GaussianBeam
the red filled shape is the model of the CELIA amplifier beam propagation with a divergence of 4.46 mrad
(the 2 black dots is the measurement of the beam size without any lens to change the beam propagation). |
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Telescope / amplifier output, posted by Manar Amer at Optical room about lasers and optics
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Note the correct beam divergence is approximately ~ 2.3 mrad
M2 = 1.1 in this fit, but it is not yet optimized !!!!! could be reason for not accurate telescope
reading. |
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Telescope / amplifier output, posted by Manar Amer at Optical room about lasers and optics
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Am adjustment on the lenses position to have a smaller waist.
+ 250 mm @ 88 cm from amplifier
-150 mm @ 111 cm from amplifier |
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Telescope / amplifier output, posted by Manar Amer at Optical room about lasers and optics
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We increased the power of the amplifier up to 10 W to see if there is a change in the beam shape at the injection point or the transmission.
There was no change in the shape of both of them from the reading at 1 W (with only the 2nd stage on)
Only saw an increase in the transmission power, which is expected. |
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Telescope / amplifier output, posted by Manar Amer at Optical room about lasers and optics
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removing the reading which is not correct (wrong use of software)
redone a reading similar using a lens of focal 250 mm got a FWHM-X = 0.64 mm , FWHM-Y = 0.84 mm
using the vertical to calculate the divergence, we get divergence ~ 2.17 mrad which is closer to fit obtained for the beam profile by taking |
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unsuccessful telescope design :-(, posted by Ronic Chiche at Optical room about lasers and optics
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we wanted to calculate the right telescope with 2 spherical lenses.
1) we have the FP cavity mode size which is 0.58mm at the input mirror and 0.7mm at the output mirror.
2) we planned to measure the laser beam at the output of the amplifier working at P=1W (2nd stage ON only). |
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2nd stage CELIA amplifier, posted by Ronic Chiche at Optical room about lasers and optics
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| today, we measured the 2nd stage CELIA amplifier pump wavelength : 970-990 nm |
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2nd stage CELIA amplifier, posted by Ronic Chiche at Optical room about lasers and optics
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today we did several test with the Dichroic shortpass mirror (Thorlabs DMSP1000) and with a 10nm optical filter around 1030nm (which works in tranmission
at AOI=0).
one used the dichroic mirror in reflection: one should cut the pump @970-990nm and we should keep only the signal @1030nm. |