Continuum Surelite EX 10, Operation And Maintenance Manual

Page: 88 / 114

Continuum Surelite Laser
78 996-0207
Figure 52 Flashlamp signal
CAUTION!
The following adjustments should be made with the
Q-switch off (using the SELECT button on front of
PCU, toggle to pulse division and set value to P00), the
lamps flashing and the cavity shutter open.
N
ECESSARY
E
QUIPMENT
•
oscilloscope with 1
Μ
input (fast scope not required)
• 1 photodiode rise time of ~1 ns
• 1 Styrofoam high density beam block
•
1 metric Allen wrench set
S
TEPS
1. Place a beam block in the beam path ~12" from the output so that it intercepts the
laser output.
2. Place a photodiode so that it monitors the light scattered off of the beam block.
3. Set up an oscilloscope (does not have to be a fast scope).
•
Connect the photodiode to a 1
Μ Ω
input on the scope.
•
Run a trigger BNC cable from the FLASHLAMP SYNC BNC connectors
(located on front of the PCU) to the external trigger input on the scope.
•
Set the time base to 100 µs.
4. Ensure that the PCU lamp voltage is set to the normal operating voltage.
5. Start the laser (flashlamps firing only).
6. Adjust the photodiode so that it detects a small amount of the flashlamp light and
scope displays lamp discharge curve.
7. Now open the intracavity shutter by switching the SHUTTER toggle to OPEN .
Note : To maintain thermal stabilization of the Pockels cell and harmonic
generators, the software will not allow the
SHUTTER
button to open for 20
minutes after the red
AC POWER
toggle is first turned
O
N.
8.
Check the scope display for any change in the
waveform. When the shutter is opened,
the scope display should be basically
unchanged
.
9. If the waveform starts with a gentle slope then abruptly increases to a jagged peak, the
laser is free-running.
10. If the laser is not free-running at this time, go to step 16.