Sbs Suppression - Keysight 81960A User Manual

NOTE

SBS Suppression

Keysight 81960A Compact TLS Module User's Guide
Config -> Trigger -> Feedback
The primary laser must always be turned on, if one or more secondary are on.
How to Increase Linewidth
You can use coherence control to increase the linewidth of the optical
signal output from your Tunable Laser module.
Enabling the coherence control increases the linewidth of the optical
output signal to between 50 and 500 MHz (typically). Coherence control
greatly reduces interference effects and therefore improves the power
stability in sensitive test setups.
To enable coherence control:
1 Move to the Tunable Laser channel and press [Details].
2 Move to [Mod Src] and press ENTER.
3 Move to <Coherence Ctrl.>, Coherence Control, to increase linewidth
to approximately 500 MHz.
4 Press Enter. The text CC appears in the Tunable Laser channel.
How to Set the Output Power of a Modulated Signal
All external modulation modes require you to set the output power. To set
the output power, see
on page 58.
SBS Suppression is a frequency modulation that allows you to launch high
optical output power into longer fibers without the impairment to
time-domain measurements that can be associated with intensity
(amplitude) modulation.
To use the SBS Suppression control (SBS-C) feature:
Refer to Figure 33
1 Move to the Tunable Laser channel and press the [Details] softkey.
2 Set appropriate values in the Freq. Modulation box:
• The Frq Mod scr > SBS-Ctrl field is fixed, since SBS-Ctrl is the only
frequency modulation source currently available.
How to Set the Output Power of a Modulated Signal
on page -62.
Operating Instructions 3
61