Anritsu MS9740B - Page 175

5.5 Measuring WDM (Wavelength Division Multiplexed) Signals
5-25
5
Measurement Functions
● Normalization: Calculation method for noise level
Off: Level in the wavelength range for the actual resolution
On: Normalized level in the wavelength range of the Noise BW
Noise BW: Band width used for noise level calculation.
● Detection Type: Detection method for noise level
Area: The noise obtained from the value of fitting curve at signal
wavelength. The fitting curve is calculated from the noise
waveform in the Noise Area
Point: Noise measured at point specified at Noise Point
Figure 5.5.3-2 Detection Method for Noise Level
When Detection Type is set to Point, the position for measuring noise
level can be set by
f6 Noise Position
.
● Noise Position
On: When the Noise Parameter Point is set to Left, the position is
separated by wavelength difference Δλ on the shorter wavelength
side of the optical signal wavelength λs.
When Point is set to Right, the position is separated by wavelength
difference Δλ on the longer wavelength side of the optical signal
wavelength λs.
When Point is set to Higher, the position is at the higher level of the
wavelength difference Δλ on the left or right side of the optical signal
wavelength λs (left side in Figure 5.5.3-3 (b)).
When Point is set to (L+R)/2, the position is at the average of the
levels of the wavelength difference Δλ on the left and right sides of
the optical signal wavelength λs.
Off: When the Noise Parameter Point is set to Left, the position is at the
dip level on the shorter wavelength side of the optical signal.
Wavelength (nm)
Level
(a) Area
l
s
Calculation
range
(b) Point
Fitting
Curve
Wavelength (nm)
Level
l
s
Left
Noise level
Right
Noise level
(L + R)/2
Noise level
Noise level