Keysight N7744A User Manual page 70

4
Specifications and Regulations Compliance
Figure 45 Relative port to port uncertainty
Conditions: As specified.
Return loss
The ratio between the incident power and the power reflected back from
the instrument into the input fiber, expressed in dB.
Conditions: As specified. (For attenuators: applicable to both ports
with fiber cables with high quality connectors in perfect optical
condition on both attenuator ports and the respective second port
terminated (zero reflectance).)
Measurement: With return loss meter and non-coherent source of
applicable wavelength.
Specification wavelength range
The wavelength range for which all specifications and characteristics
apply, if not differently stated.
Spectral ripple (power meter; due to interference)
A coherent input signal causes optical interference1 between reflective
interfaces within the power meter's optical assembly, including the end
face of a connected fiber. Optical interference causes a wavelength-
dependent periodic change of the power meter's responsivity. Spectral
ripple is defined as ± half the difference between the highest and the
lowest power resulting from the periodic change.
Conditions: Constant input power, constant state of polarization (SOP).
Connector as specified. Other conditions as specified.
Keysight N774x Series 69