Model N-STP Operation Manual
4.2.3. Stable (Green) Indicator
When the N-STP series laser system has attained proper operating temperature, the
“Stable/OT” light is energized (green) indicating that closed loop output control is in
operation, see Figure 1-5
. The “Stable/OT” light may extinguish briefly under the
following conditions:
•
During the initial 20 minutes warm-up period.
•
During ambient temperature changes beyond the 10
C operating
temperature range.
•
Significant temperature changes to the laser head housing caused by
mounting to a large thermal inertia after the unit has been through the
warm-up period.
•
Excessive optical cavity feedback due to back reflections from optics in
front of the laser or outside instruments reflecting the beam back into the
system.
Long term optical feedback (i.e. back-reflections into the laser) resulting in the inability
of the SFA to maintain closed loop operation can result in laser and/or SFA failure.
4.2.4. OT (Red) Indicator
The same LED which energizes “green” indicating that th
e unit has reached stable
operation may energize “red” when the following conditions prevail:
•
Power to laser head switched off with power applied to SFA.
•
Failure of laser head to reach reference output power.
•
Failure of single frequency control to close output control loop.
For all these, the “red” light indicates that the mirror mount has reached its maximum
allowable temperature limit and the energy to the induction coil has been shut down.
If this condition is not addressed, the SFA will cycle between the reset and maximum
temperature limit. This will be indicated by the LED changing between its “green” and
“red” indication.
10
IMPORTANT
