Schéma Manip , posted by Blanc at Optical room about lasers and optics 
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| Ci-dessous le schéma actuel de la manip. |
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Ring light in the cavity, posted by Blanc at Optical room about lasers and optics
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We put a diaphragm in the input beam but it doesn't work to suppress the ring light only but it attenuates the whole transmitted beam (cavity mode
and ring light) viewed on the camera. |
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Reflection Line Polarization Measuremet, posted by Manar Amer at Optical room about lasers and optics
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With the help of Ronic the cavity was locked in preparation to measure the polarization of the reflection line when the cavity is locked (measurement
when it is not locked was done before)
the purpose is to compare the two measurements (locked vs not locked) |
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Problèmes Cavitée, posted by Blanc at Optical room about lasers and optics
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Précédentes ref pour lesquelles la manip fonctionnait :
Caméras :
709 ; 371 NF |
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Presentations, posted by Blanc at Other about utilities
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| Here the first part of all the presentations since the beginning of the project. |
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Presentations, posted by Blanc at Other about utilities
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| Here the second part of all the presentations since the beginning of the project. |
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Presentations, posted by Blanc at Other about utilities
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| Here the last part of all the presentations since the beginning of the project. |
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Position des miroirs et gain photodiode, posted by Blanc at Optical room about lasers and optics
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Nouvelle position des miroirs :
5.198865 ; 5.199305 ; -2.9 ; -2.9
Photodiode de transmission, gain de 60, 1MOhm osc : 2.5 V |
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Polarization Results in transmission, posted by Blanc at Optical room about lasers and optics
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After data processing, I finally find the polarization in transmissin of the FPC. As you can see below, the polarisation is not linear but elliptical.
The four ellipsies are here due to having not enougth parameters to extract with certainty one ellipse. |
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Polarisation Results of the NKT, posted by Blanc at Optical room about lasers and optics
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I made many tests about polarization and we can see some points thanks to the following figures :
1- The ellipsicity of the NKT is near to 0 (between -0,2 and 0,2) which means the polarization is rectilinear horizontale (attachement 1).
2- The power of the NKT has no influence on the polarization, verticale or horizontale (attachement 2 and 3). |
Polarisation Results of the NKT, posted by Blanc at Optical room about lasers and optics
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To have the polarisation, we must have 1 value because the laser in entry of the system has 1 polar. Due to that, the graphe of the ellipticity is not
true, it is the mean value on the following table which shows the ellipticity and the polarization.
Blanc |
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Polar cavité, posted by Blanc at Optical room about lasers and optics
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Après avoir locké avec la lockline et retiré le glan et la paire de lambda sur la voie PDH, j'ai observé que la polarisation
dans la cavité changeait en fonction de la polarisation en amont que l'on pouvait changer grâce à la paire de lambda qui se trouve
après le combiner. J'ai donc cherché à la rendre linéaire, vu que l'on a jusqu'ici préréglé |
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Polar cavité, posted by Blanc at Optical room about lasers and optics
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Après avoir enlevé le PBS en transmission de la cavité j'ai cherché à atteindre le maximum possible sur la photodiode
de transmission en faisant varier la polarisation en entrée de la cavité.
J'ai remarqué que l'on était pas très sensible (40 mV d'incertitude) lorsque l'on atteignait le maximum |
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Phase noise measurement of the Amplitude MIKAN, posted by Ronic Chiche at Optical room about lasers and optics | detectors and electronics
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Installation of the MIKAN.
powermeter (with OD1) just after the oscillator shows 440mW for 4A of the MIKAN pump current.
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Phase noise measurement of the Amplitude MIKAN, posted by Ronic Chiche at Optical room about lasers and optics | detectors and electronics
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Coupling into a 50-50% fiber coupler using the Thorlabs XYZ table NanoMax TS.
We reached 117mW after the 50% arm which means we coupled about 230mW (the coupling better than 50%).
Ronic |
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Phase noise measurement of the Amplitude MIKAN, posted by Ronic Chiche at Optical room about lasers and optics | detectors and electronics
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MIKAN phase noise and RIN measurements:
Ronic
Chiche wrote:
Coupling into a 50-50% fiber coupler using the Thorlabs XYZ table |
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PZT resonant frequencies, posted by Ronic Chiche at Optical room about mechanics | lasers and optics | detectors and electronics
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we have excited the PZT with a swept sinus wave from 1kHz to 10kHz and from 10kHz to 100kHz.
here are the 2 different spectrums:
- the 1kHz-10kHz is a standard spectrum where we see the impedance behavior of the PZT: Zpzt ~ 1/jCw |
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Optimisation de la polariation Tangor and Lockline, posted by Blanc at Optical room about lasers and optics 13x
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J'ai optimisé la polarisation du Tangor et de la Lockline en jouant sur l'angle du combiner et sur la lambda/2 de chacune des voies.
J'ai réussi à obtenir une polarisation croisée entre le Tangor et la Lockline et une polarisation quasi-linéaire
pour chacune des deux voies. |
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Nouvelles positions moteurs et calibrations camera, posted by Blanc at Optical room about lasers and optics
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Positions moteurs :
5.198865 ; 5.198596 ; -2.9 ; -2.9
Calibration caméras : |
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Modulation EOM, posted by Blanc at Optical room about lasers and optics
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EOM dans la lockline:
Image 1 (sans 2è étage): on voit la modulation en réflexion de la cavité.
Image 2 (avec 2è étage): on voit la modulation en réflexion de la cavité et il semblerait qu'elle soit présente |