Novel measurement of linear dispersion slope near the zero dispersion wavelength by four wave mixing

Four wave mixing is one of the interesting nonlinearities in optical fibers and semiconductor optical amplifiers. A new frequency light is generated from the wave mixing of three different lights. This phenomenon causes system degradation in WDM transmissions, but it can also be used for new wavelength converters for other applications such as optical PLL. FWM efficiency in fibers strongly depends on phase-mismatching which is determined by the chromatic dispersion. The dependence of FWM efficiency on the phase mismatching has been investigated for dispersion-shifted fibers. We calculated the dispersion slope from the modulation behavior of the FWM efficiency. A tunable pump wave and DFB LD probe wave were combined by a fiber coupler after each amplification through an EDFA and were launched in the dispersion shifted fiber. The launched input power was about 6 dBm for each. The polarization controller was adjusted for the maximal FWM efficiency