Transmission Measurements for the Mirrors. , posted by Manar Amer at Optical room about lasers and optics 6x
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Thursday 10 December 2020: First Test Measurement - Inside Box
The transmission ( T ) for the mirrors of SBOX
and ThomX was measured over a range from the center of the mirror up to 5mm.
The first setup was initially done while the
mirrorr is installed inside the metal box, when measuring T we observe that there is an erregular change in the power measured as we move azay from |
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Origami SN2440 133MHz laser power measurment... and failure, posted by Ronic Chiche at Optical room about lasers and optics
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we received from NKT the Origami SN2440 133MHz oscillator from repair on 2020/12/17
and we measured the power trend from 2020/12/21 until the whole winter Hollyday, during 14 days and 17h (1 273 334 s).
the power was quite constant, about 58mW (the measurement has been done with the OD2 filter and using a (x20) factor in the software to compensate |
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Origami SN2440 133MHz laser tests, posted by Ronic Chiche at Optical room about lasers and optics
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Today, we received the Origami SN2440 133MHz oscillator from repair (NKT mentioned a defective wire inside the controller....)
We immediately installed it behind an isolator (Faraday rotator+PBS+halfwave plate).
the output power is around 60mW. |
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KBox Alignment , posted by Manar Amer at Optical room about lasers and optics 7x
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Starting with the alignment of the KBox using CW Koheras.
The size of the CW output from the collimator at 1 meter from is ~ 2.4 mm, to be adjusted with lenses to match the cavity !!! (attached
image) |
SBox Alignment , posted by Manar Amer at Optical room about lasers and optics 6x
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SBox alignment, using CW laser Koheras power 1 mW
Finished M1 and M2 alignment using the diffraction patterns seen on the beam profiler,
the beam fit is not very good ?? (image taken)
Positions of Ma1 and Ma2 motors are |
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SBox Alignment , posted by Manar Amer at Optical room about lasers and optics
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After pointers and Advice from Aurélien,
improvement of the beam alignment through M1 and M2 irises was done.
To improve the image on the beam profiler, I cleaned the alignment mirrors and the windows using pure ethanol and optical lens cleaning tissue, |
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SBox Alignment , posted by Manar Amer at Optical room about lasers and optics
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Remember to update the position of the reference Irises tomorrow !!!!
Manar
Amer wrote:
After pointers and Advice from Aurélien, |
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SBox Alignment , posted by Manar Amer at Optical room about lasers and optics 9x
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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 |
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SBox Alignment , posted by Manar Amer at Optical room about lasers and optics
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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. |
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SBox Alignment , posted by Manar Amer at Optical room about lasers and optics
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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. |
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SBox Alignment , posted by Manar Amer at Optical room about lasers and optics
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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 |
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SBox Alignment , posted by Manar Amer at Optical room about lasers and optics
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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. |
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SBox Alignment , posted by Manar Amer at Optical room about lasers and optics
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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. |
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SBox Alignment , posted by Manar Amer at Optical room about lasers and optics 7x
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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. |
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Fundamental Mode TEM00, posted by Manar Amer at Optical room about lasers and optics
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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) |
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Fundamental Mode TEM00, posted by Manar Amer at Optical room about lasers and optics
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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 ???
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SBox Alignment , posted by Manar Amer at Optical room about lasers and optics
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Closing Series for Alignment.
Beating observed, beam is in the locking stages
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Fundamental Mode TEM00, posted by Manar Amer at Optical room about lasers and optics
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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 |
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Telescope - Spacial Matching , posted by Manar Amer at Optical room about lasers and optics
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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 |
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Fundamental Mode TEM00, posted by Manar Amer at Optical room about lasers and optics
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Closing series of 00 mode for FSR @ 133.33 MHz
Manar |