Anritsu MS9740B - Calibrating Resolution

3.1 Calibrating Before Measurement
3-9
3
Measurement
3.1.3 Calibrating Resolution
When measuring the level of a continuous spectrum such as the ASE level
of an optical fiber amplifier or the noise level of an LD, the measured level
is affected by the actual resolution.
The resolution is calibrated to improve the level accuracy of this type of
level measurement.
The actual resolution is adjusted using an Anritsu reference light source
before shipment. Calibration of the resolution determines the actual
resolution matching the light source being used.
Always perform auto-alignment of the optical system before calibrating
resolution.
For the definition of actual resolution, refer to 1.3 “Glossary”.
To calibrate resolution
Calibrate resolution using the following procedure.
1. Input light from a light source with the following specifications at the
wavelength used at measurement to the main frame.
Level: more than –20 dBm or more
Spectrum: single mode
2. Set the main frame as follows:
Center wavelength: wavelength of the light source
Smplg: 1001
3. Press
F8
to display Cal on the horizontal function keys.
4. Press
F2 Cal
.
5. Press
f7 More 1/2
.
6. Press
f1 Res Cal
.
7. Press
f1 Execute
to display the message “Resolution Cal in progress”.
Note:
Use a single mode oscillation light source such as a DFB laser diode
or gas laser.
In addition, always use a light source that meets the specifications.
If the light source spectrum is not single mode or the level is too low,
calibration may not be performed correctly when performing
auto-alignment of the optical system.
Calibrating resolution cannot be interrupted.
The calibration value for resolution is initialized automatically
when the measurement conditions are changed.