EXFO CT440 Series, User Manual

Page: 10 / 169

Introducing the CT440
4
CT440
Product Features

Polarization State Generator (only on CT440 with PDL option)
On CT440 with PDL option, the signal passes through a polarization state generator
(PSG) that produces one of 6 states of polarization at the output port.
Data Acquisition: Raw and Resampled Data
The interferometric system triggers data acquisition every 100 MHz. As a result, the
separation between data points is not equidistant in the wavelength domain.
This raw data acquisition is then resampled by software to display the spectrum in
nanometer, with the correct sampling resolution in picometer.

On CT440 without PDL option, the graphical user interface (GUI) provided with the
instrument enables you to calculate the TF using these resampled data points or raw
data (see
Configuring Scan Parameters on page 35).

On CT440 with PDL option, the graphical user interface (GUI) provided with the
instrument calculates the TF and PDL using the resampled data points, not the raw
data. In this case, you cannot access raw data through the GUI but you can overcome
this limitation and access raw data information by using the Dynamic Link Library
(DLL), but it is highly recommended to use resampled data for the PDL calculation.