Setup panel selections
Using the Optical Spectrum Analyzer
The System Menus
4Use the arrow keys or the numeric entry pad to set the wavelength span manually or automatically. Refer to “To Fill In a Setup Panel” on page
Span
This function selects the wavelength span for viewing the signal located by the auto measure function. If Auto is specified, the span is set wide enough to dis- play most of the signal. If a particular span is desired, deselect Auto and put the desired span in the nm dialog box. The default selection for Span is Auto.
Note
If the span is set too narrow, the auto measure operation may not complete successfully. If this happens a warning message is displayed.
Scale/Div
The dB/div selection sets the vertical scale to be used after performing the auto measure function. If Auto is specified, the measurement function sets the vertical scale to a value based on the dynamic range of the signal. If a particular vertical scale is desired, deselect Auto and put the desired dB/div in the dB dialog box. The default selection for dB/div is Auto.
AutoMeas at Marker
Selecting the ON state for AutoMeas at Marker causes the auto measure function to perform its operation at the wavelength of the active marker. This allows you to measure a signal other than the largest one found in a full span sweep. The default selection for Automeasure at Marker is OFF.
Optimize Sensitivity
Selecting the ON state for Optimize Sensitivity causes the auto measure function to set the sensitivity so the resulting measurement has a minimal amount of noise. It does this by finding the minimum in the measurement trace and comparing this value to the known sensitivity of the instrument at that wave- length. Sensitivity is then reduced until the signal is close to this minimum sensitivity or the sweep time becomes too long. The Optimize Sensitivity function is useful when viewing high dynamic range signals. The drawback to turning this function ON is that it generally requires a longer sweep time to get better sensitivity. The default selection for Optimize Sensitivity: is OFF.