EXFO FTB -5240S/5240BP Optical Spectrum Analyzer - Manual (Page 626)

Formulas Used with Your Optical Spectrum Analyzer
620 FTB-5240S/S-P/BP
Central Wavelength Calculation (Spectral Transmittance)
Central Wavelength Calculation (Spectral
Transmittance)
The central wavelength is calculated using the following equation:
Where
a is the central wavelength,

R
is the wavelength on the right at which the power is 3 dB below the
power at the nominal wavelength, and

L
is the wavelength on the left at which the power is 3 dB below the
power at the nominal wavelength.
a

R

L
+
2
------------------- =