MIRcat OPERATION
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D11-00028-02-A
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7. Laser Modes
Trigger Modes (Tune) Description
Internal Trigger
Normal Pulsed Operation. A TTL pulse is output on the back panel
TRIG
OUT
BNC that corresponds to the leading edge of the optical pulse.
Pulse parameters are set on the Settings>Laser Parameters menu. Users
must click ‘Save Settings’ to activate and store any changes.
External Trigger
A TTL pulse is Input on the
TRIG IN
BNC that corresponds to the leading
edge of the optical pulse. There is an inherent pulse delay.
Set External Trigger Mode in Settings menu.
Pulse parameters are set on the Settings>Laser Parameters menu.
Manual Trigger
The GUI will provide a button for the user to click on for the laser to step
to the next location in the Scan>Step and Measure menu.
Set Manual Trigger Mode in Settings menu
Pulse Modes (Scan)
Description
Internal Pulse
Laser pulses are generated with width, repetition rate and duty cycle
determined by user GUI or SDK settings, up to factory-programmed
limits. The TRIG OUT BNC issues TTL pulses with timing synchronized
to the leading edge of the laser pulse. Pulse parameters are set in the
Settings menu. Users must ‘Save Settings’ to store changes.
External Trigger
In this mode, applying an electrical TTL pulse to MIRcat’s ‘Ext Trig’
input will generate a laser output pulse with optical width determined
by MIRcat’s internal clock settings, provided factory-programmed
pulse width, repetition rate and/or duty cycle limits are not exceeded.
Width, Frequency and Duty Cycle settings are inactive on the GUI.
External Pulse
Applying an electrical TTL pulse to MIRcat’s ‘Ext Trig’ input will
generate a laser pulse with the same width. The laser will follow the
width, repetition rate and duty cycle of electrical pulses applied to this
input provided factory-programmed pulse width, repetition rate
and/or duty cycle limits are not exceeded. This mode allows external
control of the laser pulse train without introducing clock jitter.
NOTE: Because of an internal delay between activating the laser
current and optical emission, in this mode optical pulse width may be
shorter than the corresponding external electrical pulse width. To
compensate this, the user should apply electrical pulses that are
longer (typically by 100-200 ns) than the desired laser output pulse
width. The electrical pulse width may need to be fine-tuned.
