Keysight N777 C Series - Return Loss; Side-Mode Suppression Ratio

Keysight N777-C Series Tunable Laser Family User’s Guide 53
Definition of Terms 3
Figure 22 Relative wavelength accuracy.
Conditions: Uninterrupted tunable laser source output power, constant power setting,
constant temperature. Other conditions as specified.
Measurement: Using a wavelength meter, averaging time
≥ 1s.
Return loss
Specifies the ratio of the optical power incident to the tunable laser source
output port at the wavelength set on the tunable laser source, to the
power reflected from the tunable laser source output port.
Conditions: Tunable laser source output off.
Side-mode suppression ratio
The ratio of optical power in the main mode to the optical power of the
highest sidemode, expressed in dB:
Conditions: As specified.