JDS Uniphase SWS15100, Руководство пользователя

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Operating and Maintenance Instructions – 99
Measuring PDL of an FBG
The PDL characteristics of an FBG can be measured using the same setup for zero loss
measurement and data acquisition as for insertion loss. The difference is that the software must
be set in the PDL mode and the SOM in Polarization Mode 1. For more information, see the
Using SWS Software section.
Calibrating the Equipment
General Information
There are two parameters for which the SWS is calibrated: power and wavelength.
Power calibration is performed at the factory. It is performed for both the control and detector
modules. To satisfy ISO 9000 requirements, each detector module must be re-calibrated at least
once a year for power. The user can perform the calibration or the module can be returned to the
factory for calibration. The procedure for power calibration of the detector modules is described
in the
Calibrating Power section. If the power calibration is suspect, it can be verified using the
procedure described in the Verifying Power Calibration section.
Wavelength calibration is performed at the factory when a complete system is shipped.
However, the user must perform wavelength calibration on a receiver or control module when it
is shipped as a separate unit, or if a control module or receiver is moved from one transmitter to
another, or if an addition wavelength range is added. Re-calibration for Power is not required
when an additional wavelength range is added. It is recommended that wavelength calibration be
verified once each week when the system is in constant use and each time the system is used
when it is used infrequently.
Calibrating Wavelength in the Swept Wavelength System
When do I Confirm Wavelength Accuracy? When do I Calibrate?
The SWS15100 and SWS16100 instruments are designed to operate with a wavelength
accuracy of
±
3 pm. To verify System calibration, connect a gas reference cell (such as that
within the SOM) as you would at DUT and make a measurement. Compare measured
absorbtion line wavelengths with the tables given later in this section.
To Calibrate the Wavelength Scale:
Wavelength calibration is a relatively simple procedure that takes little time, the procedure
consists of 7 simple steps: Before proceeding, ensure that all equipment is fully warmed up, ie
switched on for at least two hours.
•
Ensure the tunable laser source is properly calibrated.
•
Connect the acetylene gas cell to your receiver.
•
Enter the Calibration Dialog Box in the SWS version 3.0.2 software.
•
Acquire a trace of the gas cell, with its pronounced absorption peaks.
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