EXFO T200S, User Manual, Page: 32 / 146

Setting the Emission Wavelength/Frequency
26
T200S
Tuning the Emission Wavelength or Frequency
Tuning the Emission Wavelength or Frequency
The
TUNE
mode enables you to tune the laser to a fix wavelength/frequency by using one of
the following method:
³
Typing a precise (absolute) emission wavelength or frequency value: see Setting the
Emission Value (Absolute Tuning) on page 27.
³
Increasing or decreasing the emission wavelength/frequency laser position by applying
a predefined step relatively from the absolute wavelength/frequency: see
Applying a
Predefined Step (Relative Tuning)
on page 28.
Selecting the Tune Operating Mode
Two modes are available to tune the laser:
³
High accuracy mode
The High accuracy mode provides optimum accuracy when the laser moves to a
wavelength/frequency value you have manually entered: when you modify the
wavelength/frequency value, the laser moves to the absolute wavelength or frequency
position, with optimum absolute accuracy (according to your laser optical
specifications). Activating this setting may slightly slow down the move of the laser to
the entered position.
If the button is displayed on screen, high accuracy performances are not
guaranteed because the T200S needs internal referencing (see Performing Internal
Wavelength Referencing on page 37).
³
Optimized linewidth mode
The Optimized linewidth mode enables you to get the minimum possible linewidth
when the laser is fix and stable, and to perform fine tuning. This mode slightly increases
the stabilization time, and disables the high accuracy setting (accuracy may differ from
specification).
To select the Tune operating mode:
1.
In the TUNE mode window, touch the button.
The mode setting menu appears.
2.
In the Tune parameters area, select the wanted operation mode:
In the Parameters area of the TUNE window, the corresponding icon appears:
³
icon for High accuracy mode .
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icon for Optimized linewidth mode
The selected mode will be applied at the next tuning operation.