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N777-C Web User Interface Reference
How to Lock/Unlock the Instrument?
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The following modulation modes are available:
•
OFF - No modulation
•
Coherence - You can use coherence control to increase the line width
of the optical signal output from your Tunable Laser instrument.
Enabling the coherence control increases the line width 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.
The N777-C instruments also allow adjustment of the line width
broadening with the "Coherence Level" setting. A level of 100%
corresponds to minimal broadening. The default level is usually a good
setting.
•
Wavelength Locking - You can choose wavelength locking as the
modulation source, so the change in output wavelength is roughly
proportional to the voltage you apply to the input BNC connector on
the front panel of your Tunable Laser instrument.This enables you to
fine tune the output wavelength within a limited wavelength range.
Wavelength locking may exhibit some hysteresis effects. The
wavelength change may differ slightly when you increase voltage from
when you decrease voltage.
If you modulate the input signal, the amplitude of the wavelength
change of the modulated optical output reduces with increasing
modulation frequency.
Locking the instrument avoids to turn on the laser of the tunable laser
instruments. This helps in avoiding accidents that are caused due to laser.
To lock a device;
1
On the Control Instrument page, click to Settings > Measurement
Settings and then go to Device Locked option.
Keysight N777-C Series Tunable Laser Family User's Guide