Performing Measurement Scans
CT440
45
Synchronizing the CT440 with External Measurements
The following figure illustrates the hardware setup for external TF measurements with a
CT440 SMF.
CT440 Pulses
During the scan of the laser, the CT440 generates TTL pulses at the
Trigger Out
BNC
connector.
The sequence of pulses depends on the resolution (
Sampling res. (pm)
) set in the
Scan
Parameters
window: if a resolution of
n
pm is selected, then a trigger pulse over
n
pulses
comes out of the CT440. For more details on data acquisition, see
The time duration of the generated pulses is around 4
s.
The separation between pulses depends on the following settings:
the scan speed of the laser
the selected resolution in the CT440.
For example, for a speed of 100nm/s and 1 pm resolution, the time slot between pulses will
be roughly 10
s ((100nm/s /1pm)
-1
).
The CT440 provides a sequence of TTL pulses in the wavelength domain, so separation
between pulses is not equidistant as it would be in the frequency domain.
Before starting:
Make sure you have a BNC 50
Ω
coaxial cable.
Summary of Contents for CT440 Series
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