2-8
Using the Instrument
Setting Up Measurements
video bandwidth and sensitivity, it is recommended that either the sensitivity
or the video bandwidth be changed, whichever is the most important to the
measurement task being performed.
To reduce noise, you can select a narrower video bandwidth to improve
repeatability and sensitivity or select a wider video bandwidth to shorten over-
all measurement time. This selection allows the choice between repeatability
and measurement time based on your measuremen t requirements. The nar-
rower the video bandwidth, the longer the sweep time.
1From the front panel, press Bandwidth/Sweep > Video BW.
2Toggle to select the video bandwidth automatically or manual ly.
3Use the knob, step keys, or numeric entry pad to enter the desired value.
Note For measurements with slow polarization scrambling, use trace averaging to
improve measurement repeatability. Trace averaging is faster than video
filtering for the slow polarization scrambling application.
Using Span to Zoom In
To see a more detaile d view of the dev ice’s response, decrease the wavelength
span to expand the trace. This will enable you to precisely focus in on th e
desired measurement area. Refer to “Span” on page 3-86.
Press Wavelength > Span and reduce the span by entering the value of 2
nm.