Laser Beam Analyzer OPERATOR'S MANUAL LBA-700/708/710/712/714PC

Chapter 5 TRIGGERING TYPES & CAPTURING METHODS
5.1 Triggering the LBA-PC
The LBA-PC can support four basic types of triggering:
• CW (or no trigger required), for lasers whose light output is continuous or pulsed at such a
rate as to appear continuous to a camera (typically faster than 1000 Hz).
• Trigger Out, for lasers that can be pulsed by the LBA's trigger output.
• Trigger In, for lasers that can supply a trigger pulse to the LBA's trigger input.
• Video Trigger, for pulse lasers that cannot be either triggered by the LBA nor provide a
trigger pulse to the LBA.
Note: Your degree of success with the various trigger modes will be linked closely to the type of camera you use.
Most cameras will operate well when observing CW laser beams. A linear (or predictable) response to
light and good spatial uniformity are all that is usually needed for a camera to run successfully with the
LBA-PC.
In Trigger Out mode, the timing of the arrival of the laser pulse is critical in successfully capturing all
of the beam's energy. This is particularly true when employing Line Scan, X/Y Scan and Tube style
cameras, which read out their images in a line-by-line and pixel-by-pixel destructive manner. Frame
and Interline transfer cameras are less sensitive to pulse timing. The LBA-PC provides a Trigger Out
Delay feature that positions the laser trigger pulse for Frame and Interline transfer camera
operation.
The Trigger In mode is only appropriate with Frame and Interline transfer cameras. This mode will
capture pulsed images with a high degree of success but may occasionally miss a pulse or distort the
acquired image. The Trigger In mode will usually capture images with a hit rate better than 95%.
The hit rate for Interline cameras is slightly better than for Frame transfer types. In general, this
trigger mode has become less useful and is being replaced by the Video Trigger mode, see below.
The Video Trigger mode is only appropriate with Frame and Interline transfer cameras. It will have
a hit rate of about 99% for short pulse lasers. This is the best possible solution when the LBA can not
fire the laser using Trigger Out pulses.
Notice: Trigger In and Video Trigger modes will not work well with X/Y scanned, Line scanned (CID) and Tube
cameras. These cameras employ destructive readout techniques. If your laser pulse occurs in the middle of the
readout cycle, only half of the image will be captured.
5.1.1 A Note to Pulse Laser Users
The LBA-PC is designed to operate best when it can fire your laser. Most errors in timing and/or data
acquisition are due to various camera quirks inherent in most commercially available cameras.
Spiricon is constantly evaluating and testing new camera technologies and looking for the best
cameras for a variety of applications. Contact Spiricon’s Sales Department for the latest information
regarding camera selection.
Operator’s Manual LBA-PC
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