Keysight Technologies N4373D, User Manual

Page: 143 / 176

Definition of Terms
Keysight
N4373D Lightwave Component Analyzer, User’s Guide 141
Operating input wavelength range
The wavelength range on the LCA optical input for which the
LCA system is designed.
Optical return loss (LCA optical input)
Ratio between incident optical power at LCA optical input and
reflected optical power, expressed in dBo.
Output wavelength
Center of gravity wavelength of the signal at LCA optical output.
Wavelength is defined as wavelength in vacuum.
Phase uncertainty
When measuring the phase difference of the harmonic signals
between DUT input and DUT output at a given modulation
frequency, phase uncertainty specifies the maximum deviation
between measured and actual phase difference.
Measurement:
Based on a reference RF O/E receiver.
Relative frequency response uncertainty
When taking the difference between measured Responsivity of a
device under test and actual (true) responsivity in dBe over
modulation frequency, the system relative frequency response
uncertainty is ± half the peak-to-peak difference.
Conditions:
Modulation frequency range as specified. Other
conditions as specified.
N O T E
OMI is a value between 0% (no modulation) and 100% (full modulation).
N O T E
For E/O and O/E, phase uncertainty excludes the effect of a (constant but
unknown)
Group delay (GD) offset (resulting from a path length
uncertainty in the LCA system). A group delay offset
D
GD at modulation
frequency f
mod
causes a phase change of Dj = 360° - D GD - f
mod
expressed in degrees .