Finesse vs power by difference between main and second resonance, posted by Loïc Amoudry at Optical room about lasers and optics
|
Measurement on 24/10/18
Loïc
Amoudry wrote:
Measurements show that ratio decrease versus power. BUT, the second |
|
Finesse vs power by difference between main and second resonance, posted by Loïc Amoudry at Optical room about lasers and optics
|
Measurement on 25/10/2018
Loïc
Amoudry wrote:
Measurements show that ratio decrease versus power. BUT, the second |
M1 transmission measurement, posted by Loïc Amoudry at Optical room about lasers and optics
|
Center of M1:
I (A)
Input power (mW)
Transmitted
power (mW)
Transmission (ppm)
0
78
0.01477
189
4
16500
3.2
194
|
Change of the 3 ULE mirrors by 3 spare ULE mirrors, posted by Loïc Amoudry at Optical room about lasers and optics 
|
| First finesse measurement 20 266, FSR 133.351 MHz under vacuum |
|
M4 transmission measurement, posted by Loïc Amoudry at Optical room about lasers and optics
|
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 |
|
M4 transmission measurement, posted by Loïc Amoudry at Optical room about lasers and optics
|
Loïc
Amoudry wrote:
The kept transmission for M4 is 2.17 ppm. Which
is the value measured after alignement (center of the mirror). |
|
M1 transmission measurement, posted by Loïc Amoudry at Optical room about lasers and optics
|
At different positions, transmission give 194, 193, 208, 200 ppm?
Loïc
Amoudry wrote:
Center of M1: |
|
First run with spare mirrors, posted by Loïc Amoudry at Optical room about lasers and optics
|
I (A)
Trans (mW)
Coupling (%)
Pin
(W)
Gain
0
4
|
|
Mirrors cleaning, posted by Loïc Amoudry at Optical room about lasers and optics
|
The new mirrors didn't give expected results. Then the 4 old mirrors have been sent to LMA on 12/11/18 for a cleaning and caracterization before
and after cleaning. Also asked for a diffusion/absorption map on the mirrors if possible. They didn't really answered on what will they do.
Received on 13/11/18 by LMA. |
|
Mirrors features, come back from LMA, posted by Loïc Amoudry at Optical room about lasers and optics
|
Mirrors arrived today from LMA. Their features are damaged.
Photos avant ou après nettoyage, pas clair dans le mail de Laurent :
"J'ai commencé à nettoyer M1 et M2 avec notr methode habituelle et je me suis aperçu que sur la partie centrale |
|
Deposit on S-box mirrors after return from LMA, posted by Loïc Amoudry at Optical room about lasers and optics
|
| Cleaning on dirty surface shows something is deposited on the surface. Cleaning displaces and removes part of the deposit. |
|
Impacts on mirror's surface, posted by Loïc Amoudry at Optical room about lasers and optics
|
All the mirrors show impacts on there surface (some of them do not show deposit). Does it come from experiments or fabrication ? Are these holes
or bumps ? |
|
AFM performed on S-BOX mirrors, posted by Loïc Amoudry at Other about lasers and optics
|
| 29/02/19 - AFM has shown that spots on mirror's surfaces are bumps and not holes. |
|
Meeting with LMA people, AFM, posted by Loïc Amoudry at Other about lasers and optics
|
30/01/19 - The following powerpoint shows the results discussed with LMA people.
What came out from the discussion is:
- Their cleaning method uses demineralized water drop on a spinner. It is probably the explanation of the circular traces on the mirror's |
|
AFM+ InfraRed spectroscopy (IR spectro) has been performed, posted by Loïc Amoudry at Other about lasers and optics
|
AFM+ InfraRed spectroscopy (IR spectro) has been performed on 400kW S-BOX mirrors.
Seems that XPS made M3 and M4 dirty, but M1 have also ome dust. M2 seems clean, further AFM experiment should show that it is as clean as M1. |
|
Mirror's cleaning, posted by Loïc Amoudry at Optical room about lasers and optics
|
XPS has been proceeded on the 400kW SBOX mirrors M3 and M4 (the initial cavity spherical mirrors) in frebruary 2019. Deposited a lot of particles on
these mirrors.
All the mirrors received a Infrared spectroscopy the 12th of november 2019. Deposited glue on the non-reflective face (was used to hold them). |
|
Mirror's installed, posted by Loïc Amoudry at Optical room about lasers and optics
|
| The initial 400kW SBOX mirrors which have been cleaned ont 28th of november have been installed this morning on the SBOX. |
|
Microscope and cleaning of SBOX mirrors, posted by Loïc Amoudry at Optical room about lasers and optics
|
The mirrors went in the cavity the 28th of november (We did several power up to 30kW stored and only one to 40kW then the power went down to 2kW
during the run).
Microscope study shows that mirrors get some dust during the handling [travel from microscope to SBOX --> installation --> |
|
AFM analysis of M1, posted by Loïc Amoudry at Optical room about lasers and optics
|
AFM has been proceeded on M1 and M2.
The pdf shows the first images taken with the PLIC room Leica microscope (zoom x10 and x80).
Then the hole has been studied with a handmade microscope. It brought a better resolution. We can now see the hole has an edge, a center structure |
|
AFM analysis of M2, posted by Loïc Amoudry at Optical room about lasers and optics
|
We had enough time to proceed a quick scan of M2 which has also a hole but not centered on the mirror.
The hole is larger and higher than the one on M1. But the vertical range was to high for the AFM. Then we cannot see if there are sparkles or
not on this image. Further study with microscope would be welcome. |