Four-wave mixing (FWM) in optical fibers refers to a nonlinear interaction among four different waves, in which the energy and wave-vector must be conserved. This requirement is often referred to as phase matching and depends strongly on the chromatic dispersion. FWM has received the attention in fiber optic parametric amplifiers due to the possibility to work in more optical regions than erbium doped fiber amplifier (EDFA) widely used in DWDM networks. This feature of FOPAs makes it possible to utilize them for light amplification in S (1460 to 1530 nm) and L (1565 to 1625 nm) optical bands. Another application of FWM is the generation of equally-spaced products for the use in DWDM or WDM-PON. In the basic configuration, two pump lasers interfere in a low-dispersion fiber to induce a nonlinear phase modulation at the beat frequency, generating a few sidebands on both sides of the pump laser lines. As the sidebands propagate, further (cascaded) mixing occurs and, under proper phase matching conditions, hundreds of equally-spaced FWM products are generated, spanning a broad spectral region. Cascaded four-wave mixing can be used for DWDM optical carriers’ generation and modulation by information signal. This solution can be suitable for metropolitan area networks with average distances not more than 40 km. The first part of experiments consists of finding the optimal HNLF fiber length and pump powers for minimal DWDM optical carriers’ power nonuniformity and maximal power level. NHLF length and pump powers were varied with fixed step for 8 and 16-channel systems. The second part of experiment consists of 8 and 16-channel DWDM system performance simulation. All the generated and filtered DWDM carriers are modulated by Mach-Zehnder intensity modulator and inserted into G.652 fiber. BER level is controlled to find maximal fiber length where BER < 1e-9.