Keysight Technologies N4374B, User Manual

Page: 129 / 164

Definition of Terms
Keysight
N4374B Lightwave Component Analyzer, User’s Guide 127
Group delay (GD)
The signal delay time caused by a transmission path
(component). The group delay is derived from the phase change
d
j of a harmonic signal detected after the path (component)
resulting from a small frequency change d f
mod
of the signal,
with phase change d j expressed in degrees.
Group delay uncertainty
Specifies the maximum difference between measured and actual
Group delay (GD) .
Measurement:
Derived from Phase uncertainty .
Maximum linear average input power (optical)
The maximum average optical input power at the LCA optical
input for which the system specifications apply.
Conditions: as specified.
Maximum safe average input power (optical)
Maximum optical power that can be applied to the LCA optical
input without permanent change of the LCA’s characteristics.
Minimum measurable frequency response (noise floor)
The average of the Responsivity measured by the LCA on a DUT
with zero output, expressed in Decibel (dBm, dBo, dBe) . The
value is calculated by averaging the measured responsivity in
linear space (rather than decibel space) over the modulation
frequency within a specified modulation frequency range.
Conditions: As specified.
GD
d
ϕ
df
mod
------------------ 360
° ⁄
N O TE
For E/O and O/E, group delay uncertainty excludes a constant group delay
offset (see
Phase uncertainty ). Other conditions as specified.
CAU T ION
Applying more than the specified maximum safe input
power may damage the LCA!