Avt. Cartaxo, IMPACT OF MODULATION FREQUENCY ON CROSS-PHASE MODULATION EFFECT IN INTENSITY MODULATION DIRECT-DETECTION WDM SYSTEMS, IEEE photonics technology letters, 10(9), 1998, pp. 1268-1270
The impact of modulation frequency on the cross-phase modulation (XPM)
effect in intensity modulation (IM) -direct detection wavelength-divi
sion multiplexing systems is investigated theoretically and numericall
y. A simple expression for the XPM-induced IM is derived, verified by
simulation and its validity range is presented. The dependence of XPM-
induced IM on the fiber length, fiber dispersion, channel separation a
nd pump modulation frequency is assessed. It is shown that at very low
frequency the walkoff effect has almost no influence on the XPM-induc
ed IM efficiency which increases with the square of the frequency; at
higher frequency the IM efficiency can be reduced significantly by the
walkoff and scales linearly with modulation frequency.