Model N-STP Operation Manual
Table 1-3. Inability to Attain or Maintain Stable Output Symptoms and Causes
Symptom
Possible Cause
Action / Remedy
Output beam flickers
rapidly.
Line voltage incorrect, bad
connection, defective laser
and power supply
combination, defective
power supply or end-of-life
tube
Confirm correct line
voltage setting and make
sure connections are
secure. Confirm that the
output voltage range of
the power supply covers
the operating voltage
range of the laser and the
output current of the
power supply matches
the operating current of
the laser. Else, service will
be required. DO NOT
allow this condition to
continue as damage to
the laser may occur.
Laser power varies smoothly
between low (or off) and
high during warmup (status
LED off)
This is normal behavior. As
the laser tube expands, the
longitudinal modes move
through the neon gain curve
and after the internal
polarizer, vary in intensity.
Laser power cycles between
low (or off) or is unstable
(Status LED is green).
Back-reflections from the
experimental setup
interfering with laser
operation,
Eliminate back reflections.
Green Status LED on (Does
not cycle to red)
Beam reflection from
external optics back into the
SFA. Block the beam and
monitor with a laser power
meter and see if it settles
down
Remedy interference
from excessive feedback
by tilting reflective optics
or adding an optical
isolator.
Status LED cycles from green
to red
Laser tube output power is
below the specified value.
Tube failure or detuned
laser tube mirror mount.
Service will be required.
Power Stable at low setting
but will not lock at high
setting
Output power of N-STP-912
laser head less than 1.15mW
or N-STP-910 laser head is
less than 0.7 to 0.9mW (see
output power range on
certification sheet).
Tube failure or detuned
laser tube mirror mount.
Service will be required.
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