Anritsu MS9740B - Page 173

5.5 Measuring WDM (Wavelength Division Multiplexed) Signals
5-23
5
Measurement Functions
● Level
Detection Type: Detection type of Signal level
Point: Point level for Signal wavelength
ΣPower: Total level for Signal Span wavelength range
Signal Span is set in the range of 0.01 to 50.00.
Figure 5.5.2-4 Measurement Method for Signal Level
The optical signal level when Point is set (L
S,Lin
) is calculated by the
following formula:
)()(
, sigsig
LinS
NPL ll −=
(W)
P(λsig): Level at detected optical signal wavelength
N(λsig): Noise level at detected optical signal wavelength
When ΣPower is set, the optical signal level is calculated by the
following formula:
)(
*
1
*)}()({
1
,
iesActRSampl
Span
NiPL
n
i
sigLinS
a
l
−
−=
∑
=
(W)
n: Data count in the range of Signal Span
Span: Span (nm)
Sampl: Sampling point
P(i): ith data level (W)
ActRes(i): ith data Actual Resolution
α: Equipment dependent power correction
coefficient
Note:
When the wavelength range set at Signal Span does not fit within
the screen, only the data for the on-screen wavelength range is
totaled.
At Point
Signal Span
Level:
Level at Signal
Wl point
At
Σ
Power
Level:
Integral value in
the range of
Signal Span
Signal Wl
Signal Wl