5-5
IM AQ6370D-01EN
Measurement
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App
Index
Explanation
Wavelength Display Mode
• Displays the measured waveform with the wavelength on the X axis.
• The measurement scale and display scale are set based on the wavelength.
• The X axis unit for marker values and analysis function results is wavelength.
Frequency Display Mode
• Displays the measured waveform with the frequency on the X axis.
• The measurement scale and display scale are set based on the frequency.
• The X axis unit for marker values and analysis function results is frequency.
Display Units of the X-Axis and Marker Values
The display unit for the marker value (wavelength or frequency) can be set independently
of the waveform display’s horizontal axis units (wavelength or frequency) that were
specified using the HORIZON SCALE nm/THz soft key under SETUP. (Default: nm)
(This key can be used to enter settings such as frequency display mode on the X axis
and wavelength display mode for the marker value.)
Also, the MARKER UNIT nm THz soft key’s setting changes in conjunction with the
setting of the HORIZON SCALE soft key. However, changing the MARKER UNIT nm THz
soft key’s setting does not change the setting for the HORIZON SCALE nm/THz soft key.
Note
The MARKER UNIT nm THz soft key’s setting changes in conjunction with the setting of the
HORZN SCALE soft key. However, changing the MARKER UNIT nm THz soft key’s setting
does not change the setting for the HORIZON SCALE nm/THz soft key.
LOG SCALE **.*dB/D
This key switches the vertical axis to LOG display and sets the level scale.
The setting range is 0.1 to 10.0 dB/DIV. Settings can be adjusted in steps of 0.1 dB.
If you press the COARSE key you can change the numerical value in 1-2-5 steps, for
example: 1dB/DIV -> 2dB/DIV -> 5dB/DIV.
When the setting is changed, the displayed waveform is redrawn according to the
changed scale.
If the value is set to a scale larger than 5 dB/DIV in range fixing mode (SENS:NORMAL/
HOLD) or pulse light measurement mode, the waveform will not be correctly measured in
the vertical direction so a warning is displayed.
Measurement Sensitivity and Vertical Axis Effective Range
When the measurement sensitivity is set to NORMAL HOLD, the internal amplifier has
a fixed gain. Five different gains are set automatically according to the reference (REF)
level setting. However, the effective range of measurement data is limited to the following
range, using the reference (REF) level (dBm) as a reference.
REF-20 dBm < (effective range) < REF+10 dBm
If the level scale is set to 10 dB/DIV, the display would exceed the effective range, so the
areas at 10 dB from the screen stop and 20 dB from the bottom are inaccurate.
When measurement sensitivity is set to NORMAL HOLD, we recommend setting the
level scale to 5 dB/DIV or less.
Under the measurement sensitivity settings NORMAL AUTO, MID, and HIGH 1 to 3,
an automatic gain is used, permitting measurements over a wide level range through a
single sweep. Select the appropriate sensitivity level based on the light reception level
required for the particular measurement application.
5.2 Horizontal/Vertical Axis Settings
