Laser Beam Quality - NORTHROP GRUMMAN Patara I User Manual

No Output Power
Laser Flicker

Laser Beam Quality

© 2018 Cutting Edge Optronics, Inc.
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.
 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.
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.
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%.
Chapter Seven: Troubleshooting
53 Patara I and II Laser User Manual