Teledyne Princeton Instruments PI-MAX 3, System Manual

Page: 120 / 250

120 PI-MAX
®
3 System Manual Issue 2
8.4.3 Static Gate Experiment [Fixed Width, Fixed Delay]
The procedure to configure a Static Gate experiment with fixed width and delay is
similar to that for a Swept Gate experiment with the following configuration changes:
• Gate Mode is configured as Repetitive;
• Gate Width and Gate Delay are configured on the Repetitive Gating Setup
dialog. See
Figure 8-26 .
Figure 8-26: Typical Repetitive Gating Setup Dialog
Refer to Section 8.4.1, Swept Gate Experiment [Fixed Width; Variable Delay] , on
page 105 for additional configuration information.
8.4.4 Single Shot Experiment
A single shot experiment offers one chance to capture an event. As in any gated
experiment, the time budget of the experiment is crucial. If there is no pre-trigger from
the experiment, a photodiode can be used to generate an electrical trigger from the
laser light. In this situation, light has to be delayed by optical means (fiber-optic cable or
mirror reflections) to allow sufficient time for the electronics to be activated after
receiving the trigger. Another important thing to note in single shot experiments is that
the CCD is set in "Continuous Cleans" mode so that there is no dark charge
accumulation while it is waiting for the trigger.
The following experiment is an attempt to capture a 60 ns fluorescence generated by a
single shot laser. The time budget for this experiment is provided in
Table 8-2 .
NOTE:
This information is important in order to choose the correct
length fiber-optic cable.
4
4
11-
012
9
_0
07
4
Table 8-2: Sample Single Shot Experiment Time Budget
Delay Source Delay (ns) Total Delay (ns)
Fiber-Optic
Cable Length
Photodiode (light
►
TTL pulse)
2 30 A minimum of 21 feet
of fiber-optic cable is
required.
Photodiode
►
PI-MAX3
(2 feet BNC cable)
3
PI-MAX3 25