Broadband and nearly flat parametric gain in single-mode fibers

Summary form only given. In optical WDM communication systems, the 35 nm gain bandwidth available with conventional EDFAs sets a limit to the increase of transmission rates. It is important to develop new optical amplifiers in several spectral ranges between 1.3 /spl mu/m and 1.6 /spl mu/m, with broad bandwidths and flat spectral gain profiles, another restrictive factor in long-haul systems involving repeated steps of amplification. Multi-pumped fiber Raman amplifiers and dual-band doped-host EDFAs are some of the presently developed devices. We study another approach based on parametric amplification which is spectrally flexible and can additionally provide low noise features and the possibility to achieve phase-conjugate wavelength conversion. We present broad and nearly flat parametric gain profiles around the zero-dispersion wavelength of single-mode fibers, obtained from modulational instability (MI) calculations and simulations of the nonlinear Schrodinger equation.