Chapter Seven: Troubleshooting
© 2018 Cutting Edge Optronics, Inc.
53
Patara I and II Laser User Manual
Pulse repetition rate is not correct:
Check the pulse rate frequency (PRF) in
eDrive or the frequency of trigger pulses.
Laser is misaligned:
Perform the laser power optimization procedures as
described in the
Optimize Laser Performance
section in
Chapter 5: Maintenance
to bring the power back.
Internal optical damage to the laser, contaminated rod, or aging diodes:
If the
laser power cannot be restored after optimization, contact Northrop Grumman for
service.
No Output Power
Verify the operating current is set at the operation point.
Verify the Q-switch is set to hold off and the laser is triggered at preset PRF
with an internal or external triggering source.
Verify the shutter light on the front panel of the eDrive is turned on indicating
that laser shutter is open.
Verify there are no interlock warning messages on the eDrive and that the
eDrive is supplying the correct current.
Verify the eDrive is not gated off externally and not commanded to low or 0
percent Q-Switch power.
Laser Flicker
When the external perturbations are applied to the laser system, the laser exhibits
flickering.
Verify the laser performance is optimized.
Verify there is no strong vibration forces applied to the laser head.
Verify that the flow rate to the laser head is above 1.5 gpm and the water flow
is not intermittent.
Verify the laser has good output power. A laser with high modulation loss or
low operating current is sensitive to perturbations.
Verify the operating current is stable.
Verify the Q-switch hold off is good.
Laser Beam Quality
Figure 7-1
shows a typical laser output beam at operating current. Per
specification, the roundness of the beam profile at the beam waist should be
greater than 90%.
