EXFO OSA20 User Manual page 85

Envelope

The Envelope algorithm defines an envelope from the peaks of the spectrum above
Mode Threshold (linear fit between each peak on log scale) and deduces the
width based on that envelope, as shown in the following figure.
RMS/RMS Peak

The RMS and RMS Peak algorithms calculate the root mean square value σ of the
power data above a given Width Threshold, taking the full power data (RMS) or
simply the Power at Peak (RMS Peak) for the calculation.
OSA20
Width Threshold
Modal ON
Fit ON
Modal ON
Modal OFF
Fit OFF
Width Threshold
Mode Threshold
Setting Up Spectral Width Analysis
Modal ON
Fit ON
Modal ON
Fit OFF
Wavelength or Frequency
Wavelength or Frequency
Analyzing Traces
77