Analytical Calculation of the Number of Second Order Four-Wave-Mixing Products in Optical Multichannel Communication Systems

Four-wave mixing (FWM) is one of the major limiting phenomena in dense wavelength division multiplexing (DWDM) optical fiber communication systems with multiple frequency channels when the fiber input power is large and / or the channel spacing is too small. Any three frequency channels can interact to create a new signal components through FWM nonlinear process. The new signal can interact with the original signals to create a new other signal components through the same nonlinear process. We develop (for the first time) simple formulas and algorithms for estimating the number of second order FWM products. These algorithms can be helpful for DWDM network communication systems.