HP 86037B, Instruction Manual

Page: 44 / 204

2-26
Operation
The Review Data Window
The amount of scatter of the directly
calculated dispersion has minimal
impact on the accuracy of the zero-
dispersion wavelength because the
zero-dispersion wavelength is
obtained from the fitted curve. When
the wavelength step is very small
(less than about 0.01 nm), and a
wavelength meter is used with the
system, it is possible for two or more
data points to have the same wave-
length due to imperfect tuning of the
tunable laser source. When this hap-
pens, it is no longer possible to
directly calculate the dispersion from
adjacent group delays because the
denominator in the above equation is
zero. In such cases, the dispersion is
calculated by using the last data point
of the group of data with the same wavelength. However, when the group
delay data is automatically stored in the database, all points are saved.
The Gain Graphs and List tabs
These tabs show the measured gain and (for reference) the measured relative
group delay. The information from the
Gain Graphs
and the
Gain List
tabs can be
viewed only if both the CD and gain measurements have been performed. In
the graphs, the displayed points are connected by straight line segments, with
no curve fitting.
If a wavelength meter was used in the measurement setup, the actual mea-
sured wavelengths are displayed.