Our
image intensified high speed cameras are mostly operated as trigger
slaves, where
the
trigger pulse is generated elsewhere in the application setup and
connected to the camera. However, in certain applications it seems to
be quite useful to operate the camera as trigger master and supply an
internally generated trigger pulse to other components of the
experiment. In this context, to trigger the camera means to initialize
the gating of the camera, i.e. to
initialize the opening of the shutter.
Regardless of the camera usage, as trigger slave or trigger master, a
trigger delay unit is needed to synchronize the time slot of the gating
pulse to the experimental event under investigation. Therefore, a
programmable built-in trigger delay unit is supplied as standard with
all our cameras. It may be easily adjusted in time delay steps of 10ps
by this high speed camera remote control console. These 10ps delay
increments e.g.
allow for fully time resolved
sub-nanosecond flurescence lifetime imaging microscopy,
where the fluorescent decay can be scanned in 10ps intervals.
If the
camera is used as trigger slave you may need to delay its gating
with respect to the received trigger pulse.
Example: The
external trigger pulse may be derived from the ignition
pulse of an electrical discharge unit. It will take some time until the
breakthrough has proceeded to that point which is under your
investigation. Thus, the gating must be delayed by this
time regarded
to the incoming trigger pulse. In this case, you simply set the
internal trigger delay to the desired time lag by the cameras remote
control to precisely adjust the point of exposure in time.
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If
the camera operates as trigger master it will be neccessary to delay
its internal gating with respect to the internally generated trigger
pulse, which in this case initializes the operation of other parts of
the experimental setup.
Example: If
the
internal generated trigger pulse initializes a laser
the camera gating must be delayed until the laser pulse is performed
and e.g. an excitation process has completed. Also in this case the
internal trigger delay unit provides the neccessary time lag as
described above.
If the high speed camera is operated as trigger master the maximum
trigger
frequency which is internally generated equals twice the actual frame
rate. If a lower trigger frequency is desired, an external counter
divider may be used for this purpose.
If the camera operates as trigger slave it is even possible to trigger
it by a periodical or recurring trigger signal, also with high
frequencies. In this case our built-in single trigger discriminator may
pick out the first trigger edge and ignore the succeeding ones. The
trigger discriminator also allows for a freely programmable number of
acceptable trigger edges, up to a total of 127. |
