5-27
IM AQ6373-01EN
Mesurement
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App
Index
Explanation
“UNCAL” Display
When manually entering the number of samples, if the number of samples is too small
relative to the appropriate number of samples as determined by the span and resolution
setting, data can be dropped. Therefore, if the span, number of samples, and resolution
settings on the instrument are unsuitable, the UNCAL mark
is displayed.
If not needed, you can turn the UNCAL display OFF.
For the procedure, see section 9.5, “Other Settings.”
Conditions under Which “UNCAL” Is Displayed
“UNCAL” is displayed when a single or repeat sweep is started based on the following
relationship between span, setting resolution, and set number of samples:
Setting resolution
Span
x 5 < Set number of samples - 1
Waveforms When Set to High Resolution
When the resolution is set high (to 0.01 nm or 0.020 nm) for measurements of a light
source such as a DFB laser in which with the spectral width is narrower than the
instrument’s resolution, very small spikes may occur at the skirts of the waveform. This
type of spike occurs due to characteristics of the optical block and is not an indication of
any problem. Even if such spikes occur, satisfactory performance in terms of resolution,
dynamic range, and the like can be ensured. These spikes will disappear if the resolution
is set to a coarser value.
Resolution Setting of 0.01 nm
This setting is valid when the measured wavelength range is 400 to 470 nm. You can set
0.01 nm in other wavelength bands, but the resolution is the same effective resolution
value as when set to 0.02 nm.
Resolution Setting of 10 nm
This setting is valid when the measured wavelength range is 470 to 1200 nm. You can
set 10 nm in other wavelength bands, but the resolution is the same effective resolution
value as when set to 5 nm.
Also, the effective resolution when set to 10 nm is approximately 8 nm even at the
widest.
5.7 Wavelength (Frequency) Resolution Settings