Cavity Lock , posted by Manar Amer at Optical room about lasers and optics | detectors and electronics | software
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Closing the series for the setup
The cavity was only locked @ 133.33 MHz but the Finesse was not measured
The FSR was changed to match the new laser MENHIR 216.6625 MHz |
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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 |
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Divergence of the CW beam after collimator , posted by Manar Amer at Optical room about lasers and optics
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Closing the series of the telescope for the beam @ 133.33 MHz
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SBox Finesse at 216.6625 MHz, posted by Manar Amer at Optical room about lasers and optics | vacuum
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Max Finesse obtained @ 4 mirror setup was ~ 19 300
With M1 from ThomX , M2/M3/M4 from SBox
Manar |
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SBox Finesse at 216.6625 MHz, posted by Manar Amer at Optical room about lasers and optics | vacuum
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Manar
Amer wrote:
Max Finesse obtained @ 4 mirror setup was ~ 19 300 |
2 Mirror Setup @ 216.6 MHz, posted by Manar Amer at Optical room about lasers and optics | detectors and electronics 
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The SBox cavity setup was changed to have only 2 mirrors M1 plane and M2 spherical, both from ThomX
Distance between the mirror ~ 72 cm , increased from 70 cm to take into account the thickness of the ThomX mirrors
Two lenses (300 mm @ 50 cm , 200 @ 104 cm) were placed to have the beam radius ~ 0.55 mm. |
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Images of ThomX mirrors , posted by Manar Amer at Optical room about lasers and optics
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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. |
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Images of ThomX mirrors , posted by Manar Amer at Optical room about lasers and optics
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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 |
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2 Mirror Setup @ 216.6 MHz, posted by Manar Amer at Optical room about lasers and optics | detectors and electronics
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The cavity was realigned using irises instead of pinholes, gave a better alignment.
The inside of the box, the spherical and the injection mirror were cleaned and placed back inside the box.
we see beating of fundamental mode, previously at the transmission point we placed a wedge to split the beam which resulted in an elliptical |
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2 Mirror Setup @ 216.6 MHz, posted by Manar Amer at Optical room about lasers and optics | detectors and electronics
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Update for Finesse measurement, The cavity was put under vacuum ~ 1.1*10^-1 mbar
and the alignment and coupling improved.
FSR = 210.1 MHz |
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FSR change & Finesse Measurements , posted by Manar Amer at Optical room about lasers and optics | detectors and electronics
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The FSR of the 2 mirror (plan-spherical) Cavity was adjusted from 210 MHz to reach 216.643 MHz
it was done by having two reference irises, one at the injection point and one at the reflection
then changing the position of injection plan mirror to slightly closer distance and monitoring the reflection on the oscilloscope to be max. |
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FSR change & Finesse Measurements , posted by Manar Amer at Optical room about lasers and optics | detectors and electronics
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Yesterday evening the cavity was Vacuum pumped up to pressure of 5.5*10^-2 and locked
changed FSR to be 216.662 MHz and alignment a little and measured the Finesse
in Vacuum we have average Finesse = 30341.6265 |
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FSR change & Finesse Measurements , posted by Manar Amer at Optical room about lasers and optics | detectors and electronics
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a Finesse of 30k with the present mirrors :
T1=120 ppm ;A1=(2.6+1) ppm;
T2=1.5 ppm ;A2=(4.5+0.27) ppm; |
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Installation of D-shaped mirror / Alignment, posted by Manar Amer at Optical room about lasers and optics | detectors and electronics
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To prepare for the amplifier. I installed the D-shapped mirrors after cleaning (using aceton and ethanol) between the cavity 2 mirrors.
Before closing, I observed the back reflection from M1 (injection mirror). both the injection and reflection lines were off, due to that there
was an internal reflection hitting the walls of the cavity. |
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CELIA amplifier installation, posted by Manar Amer at Optical room about lasers and optics | detectors and electronics | software
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The amplifier was installed on the optical table next to SBox table.
The CVBG that will be used for stretching before amplification needs cleaning (they are very fragile, 'ask victor for best method')
The software to drive the diodes of the amplifier we have is not the compatible one. |
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CELIA amplifier installation + chiller, posted by Manar Amer at Optical room about lasers and optics | detectors and electronics | software
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Amplifier placed next to the pulsed laser on the table under the airflow
The output is in free space with height from the table of about 10 cm, note the injection height into the cavity is between 14 - 15 cm.
a power cable is placed but not plugged. |
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Installation of D-shaped mirror / Alignment, posted by Manar Amer at Optical room about lasers and optics | detectors and electronics
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The D-shaped mirrors are installed properly and not cutting the path of the beam.
The cavity has been aligned again and 00 modes beating observed, and external reference points has been placed.
Manar |
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Alignment / Table setup , posted by Manar Amer at Optical room about lasers and optics | detectors and electronics | software
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The current setup of the optical table attached.
The cavity is aligned and the lock of the fundamental mode has been attempted, but the mode is drifting too quickly to be able to follow.
I have placed the cavity under vacuum for a better stability. |
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CVBG stretching / Fiber Injection , posted by Manar Amer at Optical room about lasers and optics | detectors and electronics | software 7x
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Before injecting into the amplifier, the pulse needs to be stretched using a CVBG, type attached.
the CVBG is to be used at a small angle, the beam shape and spectrum after the PBS is attached.
After measuring the beam profile, a mirror was placed to direct all the power for fiber injection |
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CELIA amplifier installation + chiller, posted by Manar Amer at Optical room about lasers and optics | detectors and electronics | software
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The software to control the CELIA amplifier is on the laptop that was placed in ThomX bunker.
I have placed it in the PLIC room next to the SBox table.
it is called 'Alphanov Control Software' |