HP 86037B, Instruction Manual

Page: 32 / 204

2-14
Operation
The Main Window
Grating Related Parameters area
The
Grating Related Parameters
area allow you to optimize measurements for grat-
ing based devices such as fiber Bragg gratings. Options are available for
improving the wavelength accuracy and measuring absolute group delay
instead of the default relative group delay. For more information on measuring
grating-based devices, refer to “Measuring Grating Devices” on page 1-11.
TLS Wavelength Feedback Mode
If your system includes an
HP 86120 multi-wavelength
meter, you can use this area to
increase wavelength accuracy of
the measurement results. Mea-
surement speed, however, will
be increased. Selecting the
On check box causes the multi-wavelength meter
to provide wavelength feedback to the laser. The Tuning Accuracy field sets the
required accuracy.
Absolute Group Delay Measurement
Select
On
to include absolute
group delay measurements to
your tests. This selection auto-
matically turns off the curve fit
algorithms available in the review
data window. Of course, you can still select a curve fit algorithm after the test
completes if you desire. The
Measurement Wavelength
field allows you to set the
wavelength at which the absolute group delay is measured. For narrow band
grating measurements, this wavelength should be inside the passband of the
filter.