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App-10
IM AQ6373-01EN
Appendix 2 Details of Each Analytical Functions
This section describes the algorithms for analyses using the ANALYSIS 1 soft key in the
ANALYSIS. ANALYSIS 1 provides such functions as collective analysis of various light
sources, POWER analysis, SMSR analysis, and PMD analysis.
SMSR Analysis Function
Use the optical spectrum after the measurement of DFB-LD to analyze the SMSR (Side
Mode Suppression Ratio) of DFB-LD.
Following table shows the details of parameters for NOTCH analyses.
Parameter
Abbreviation Default Value Setting Range Unit Description
SMSR MODE MODE
SMSR1
SMSR1/SMSR2 -
Execution mode during
SMSR measurement
SMSR MASK MASK
±0.00
0.00 to 99.99
nm Setting of near-peak
mask range during
SMSR1 measurement
Algorithms for analyses are described here. They differ depending on the SMSR modes.
Algorithms for each mode of analysis are described below.
SMSR1
The next highest mode peak after excluding the highest mode peak level and the mask
setting range is defined as the side mode.
MASK AREA
SMSR
Mode Peak(
L
A)
Side Mode(
L
B)
Algorithms of analysis for the SMSR1 mode are as follows:
• Perform a mode search to obtain the mode peak.
• Of the obtained mode peaks, set the point of the mode peak at the highest level (LOG)
to PA. Also, set the wavelength value of this point to
λ
A.
• Except for the mode peaks within the range of PA ±1000 × (SMSR MASK)/SPAN, set
the wavelength of the highest mode peak, which is next to PA, to
λ
B. If a relevant point
does not exist, set the wavelength value at the highest level outside the range of PA
± 1000 × (SMSR MASK)/SPAN to
λ
B. If there is more than one
λ
B, set the leftmost
wavelength value to
λ
B. Also, set the levels (linear values) for each point of
λ
A and
λ
B
to LA and LB.
• Obtain SMSR and
Δλ
from the following equations.
SMSR = LA / LB
Δ
λ
=
λ
B -
λ
A