Victor, Ronic, Manar
Today was dedicated to the study of the CVBG, and it's effect on the beam profile
we opened the box containing the 2 CVBGs : The 2CVBG are glued from the bottom on a copper surface .
Using the beam viwer, the beam line inside the two CVBG is not at the exact center but not at the edges too and not hitting the boarders.
From the sides you see two lines, one is reflection on the metal.
To observe the effect of the first CVBG by itself, we blocked the second reflection into the 2nd CVBG.
By placing the D-shaped mirror just at the entrance of the 2nd CVBG (there was just enough space to put it)
Beam Profiler + OD 10E + OD 30E + OD(not known) placed at ~ 1 m from the output of compressor.
We see clearly a much better circular shape of the beam and a better Gaussian fit,
only above 90% where we see the fit percentage going down to ~ 86% and on just the Horizontal Axis.
| Manar Amer wrote: |
|
This Morning, another reading was taken for the output of the amplifier after the compressor using 2 wedge mirrors.
In addition, a start of the calibration of a PulseCheck "Autocorrelator" to measure the pulse duration.
note, the pulsed laser used is OneFive 133.33 MHz
| Manar Amer wrote: |
|
Adding the readings 20% , 30% , 40% for output of amplifier after the compressor
| Manar Amer wrote: |
|
Readings of the beam shape and fit at the output of the compressor
differance from previous reading is that here we used wedges instead of HR mirrors.
Similar to previous readings, the beam shape deforms and the Gaussian fit is bad after 50% amplification
| Manar Amer wrote: |
|
Readings of the beam shape and horizontal (upper plot) and vertical (lower plot) axis fit at the direct output of the amplifier.
The beam shape relatively shaped like an egg.
| Manar Amer wrote: |
|
Today a second reading of the beam profile was done , with Victor ,Ronic, Aurlien and Manar
an additional set-up was made using two 4 deg wedges instead of High reflecting (HR) and Anti-reflecting (AR) mirrors.
Two reading were taken:
- at the output of the compressor with a NE30A filter on the beam profiler
- at the output of the amplifier with NE30A + NE10A filter on beam profiler
| Manar Amer wrote: |
|
Adding the fitted beam in 1D in Horizontal and vertical axis.
for 10% to 60%
| Manar Amer wrote: |
|
| Manar Amer wrote: |
|
Today: Manar, Ronic and Aurlien started the study of the beam profile of the alphanov amplifier at high power.
The setup shown in the image shows how the power is reduced by using Anti-reflective mirrors,
pick up 1 : Anti-reflective coating on both sides , pick up 2 : Anti-reflective coating on one side and High reflectivity on the other
using this method, we avoid saturation and damage to the beam profiler from the high power amplified laser
in addition, an OD3 filter is placed in front of the beam profiler. and a reflective mirror is placed close to deflect the reflection from the mirror(pick up 1) second surface.
The beam observed is relatively well shaped and fitted up to 50% of amplification is where the shape starts to deform a little and is not well-fitted by a Gaussian. (image attached shows the fit for 60% amplification)
The cause is yet to be determined, as it could only be related to the reflections that occur from the mirrors (pick up 1 and pick up 2)
*** Note be always careful at High Power :)
|
|
|
|
|
|
|
|
|