SBox Alignment , posted by Manar Amer at Optical room about lasers and optics 9x
|
Adjust the placement of the Irises (done at the start of the day, adjusted at the end
when M1 mirror was placed)
Improvement on the
Ma1 and Ma2 (The Alignment Mirrors)
Improves the alignment a bit. There is an observation where there |
|
SBox Alignment , posted by Manar Amer at Optical room about lasers and optics
|
Finished the alignment of the SBox with M1 of SBox placed, to be changed to gamma factory mirror later
Observed what seems to be transmission through M2 mirror, to be confirmed. image attached shows it
a PowerPoint attached showing the details of today's work. |
|
SBox Alignment , posted by Manar Amer at Optical room about lasers and optics
|
Last week In FP cavity we had all SBox mirrors including the damaged M1 mirror.
The beating was observed with just a slight adjustment on M4 alignment.
In addition, it was also observed while driving the piezo of the CW laser. |
|
SBox Alignment , posted by Manar Amer at Optical room about lasers and optics
|
Today; replaced the M1 SBox mirror with M1 from gamma factory , following the previous alignment.
Removed all mirrors and cleaned them one by one.
Started with no M1, placed M2 did its alignment through M3 pinhole, then placed M3 aligned it through M4 pinhole, then placed M4 aligned it through |
|
SBox Alignment , posted by Manar Amer at Optical room about lasers and optics
|
Yesterday, to find the source of why the mode is deformed, I tried to rotate the mirrors to see if there is a change.
I started with M2 and rotated it by ~ 90 degrees, there is a change in the shape of the beam.(image attached)
Will see if changing M2 to the spare M2 from SBox can fix the issue. |
|
SBox Alignment , posted by Manar Amer at Optical room about lasers and optics
|
M2 Sbox changed to spare. Alignment of M2 was redone.
With the help of Ronic , We observe fundamental mode of the cavity with higher order modes. A frequency scan on the piezo was done to find the
beating frequency , the shape is elliptical with no clear deformation. |
|
SBox Alignment , posted by Manar Amer at Optical room about lasers and optics 7x
|
The external and internal alignment was redone.
External Alignment : the collimator position moved so in order to have a good start I placed 2 metallic mirrors and did a rough retrace of it's
line through the cavity box. |
Fundamental Mode TEM00, posted by Manar Amer at Optical room about lasers and optics
|
The current setup for the SBox has a beam viewer and 2 photodiodes placed at reflection and transmission.
The CW laser piezoelectric crystal was driven using the lase lock system to observe the 00 mode.
Mode Observed and has no reflection (from what was previously seen) |
|
Fundamental Mode TEM00, posted by Manar Amer at Optical room about lasers and optics
|
Adding images from the transmission after the spherical mirrors M3 and M4 window for a resonating mode inside the cavity.
There appears to be some misalignment from the center of the mirror ???
|
|
SBox Alignment , posted by Manar Amer at Optical room about lasers and optics
|
Closing Series for Alignment.
Beating observed, beam is in the locking stages
|
|
Fundamental Mode TEM00, posted by Manar Amer at Optical room about lasers and optics
|
Images of the Transmitted beam at M2 mirror at different days.
The first one was from last week, the second from yesterday.
There is misalignment (drift due to temperature) from the position where the beam was initially. ( reference taken between centers of mode and |
|
Telescope - Spacial Matching , posted by Manar Amer at Optical room about lasers and optics
|
Divergence of the CW beam out of the collimator measured after 1 meter to be
2 x = 0.7425 mrad --> x = 0.37125 mrad
2 |
|
Fundamental Mode TEM00, posted by Manar Amer at Optical room about lasers and optics
|
Closing series of 00 mode for FSR @ 133.33 MHz
Manar |
|
Divergence of the CW beam after collimator , posted by Manar Amer at Optical room about lasers and optics
|
Closing the series of the telescope for the beam @ 133.33 MHz
|
|
Images of ThomX mirrors , posted by Manar Amer at Optical room about lasers and optics
|
Under the microscope,
the spherical mirrors show the deposit of metal dots on the reflecting surface and not on the back of the mirrors
The mirror with fewer spots near the center was used in the setup. |
|
Images of ThomX mirrors , posted by Manar Amer at Optical room about lasers and optics
|
Mirror images in the previous log showing the metal deposit of the coating of the spherical mirrors
(not sent by mail due to large size of images)
Manar |
|
Pulse duration measurement before and after CVBG (as a strecher), posted by Ronic Chiche at Optical room about lasers and optics
|
I recorded the pulse shape of the MENHIR 216MHz in its fiber injection setup.
the fiber is then connected to the Labbuddy photodiode (~ 15GHz BW) and then to the R&S RTO2000 4GHz scope (~ 100ps rise time).
1) I put a mirror just before the CVBG. |
|
"ThomX" CELIA Amplifier commissionning, posted by Ronic Chiche at Optical room about lasers and optics
|
The "ThomX" CELIA amplifier is installed on the optical table.
I added all the rubber pieces available between the 2 racks to isolate as best as possible the top rack, which embeds some fans, from the bottom
rack from which the laser beam is going out to the FP cavity. |
|
"ThomX" CELIA Amplifier commissionning, posted by Ronic Chiche at Optical room about lasers and optics
|
Beam size at the amplifier output:
to make this measurement, I switched ON only 1st and 2nd stage.
the dichroïc mirror seems to work the best in reflection at normal AOI !!! |
|
OEwaves lock and Finesse measurement, posted by Ronic Chiche at Optical room about lasers and optics
|
this morning, I locked the FP cavity with the OEwaves CW laser and the "Fred fiber amplifier" used at 500mA of pump current.
the lock was much more easy than with the Koheras.
I had to change the 10GHz EOM which seems damaged as the modulation depth is very low and does not allow a Finesse measurement by modulation |