MIRcat OPERATION
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D11-00028-02-A
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first sweep. Each process trigger only causes the system to sweep one channel and not all of the channels in
a sweep.
Once done, the system will return to the start position, set up the next scan and wait for Pin 4 to go
LO before starting the next channel scan. In either Step & Measure or Multi-Spectral Mode, the laser will
move to the first wavelength and turn on. It will then stay at that wavelength and continue to emit light
until this signal is pulled LO. The signal should be pulled LO to ground for between 250 and 500 ms, at
which point the laser will move to the next wavelength and then start firing.
Use Internal Step Mode- This mode allows the system to automatically control the next step in the scan and
outputs a TTL signal on the DB-9 Pin 2 “Tuned” signal. This allows the MIRcat Laser to be in the Master
timing mode for data acquisition. The user can program Dwell Time for the laser to pause at the step before
moving with the Internal Trigger Step Time (ms), as well as programming Off Time for the laser to turn off
between scans using the Internal Trigger Step Delay Time (ms).
Use External Step Mode- This mode waits for the user to apply a LO signal on the Process Trigger signal, Pin
4 of the DB-9 connector. This allows the MIRcat Laser to be in the Slave timing mode for external control,
like data acquisition.
Use Manual Step Mode- allows the user to click on a button in the SCAN menu GUI to step the laser thru the
scan steps. The laser will emit light while waiting for the next manual step command.
Pulse Modes-
The user can select the Internal Pulse Mode, External Trigger Mode, External Pulse Mode or
Wavelength Trigger Pulse Mode.
Use Internal Pulse Mode- uses the parameters set by the user in the Laser Parameters menu.
Use Ext. Trigger Mode- This mode uses the TTL signal applied to TRIG IN on the back-panel BNC connector;
will initialize a single optical pulse per trigger whose width is set in the Laser Parameters menu.
Use Ext. Pulse Mode- This mode uses the TTL signal applied to TRIG IN on the back-panel BNC connector;
will initialize a single optical pulse per trigger whose width is determined by the applied pulse width.
Note: If the user exceeds the allowed pulse frequency or pulse width, no optical pulse will emit and
an error message is issued.
Use Wavelength Trigger Pulse Mode- Active during the Sweep Scan mode only, uses the same pulse
parameters as Internal Pulse Mode. This mode also emits a TTL electrical pulse on Pin3 of the DB-9
connector as the laser tunes across the set range at each preset interval, using the Start/Stop Wavelength
Trigger parameters specified in the Laser Settings menu. For example, if scanning from 7 to 10 µm, and the
WL trigger start and stop are set to 7.5 µm and 9.5 µm, respectively, and the WL trigger interval is every 0.1
µm, an electrical pulse will be emitted when the laser scans crosses 7.5 µm, 7.6 µm, 7.7 µm, etc.
