Four-wave mixing for nonlinear parameter estimation in a compact ring cavity laser using Bi-EDF

Four-wave mixing is one of the major degradation effects in fiber optic systems with dense channel spacingand low chromatic dispersion on the fiber. in the long-distance wavelength-division multiplexing (wdm) opticalcommunication system, the cross talk generated from four-wave mixing in optical fibers limits the performanceof the system, which can be controlled for non-linearity purposes in optical telecommunication, especially thechannel wavelengths are set near the zero-dispersion wavelength of optical fibers. hence, a very short fibersegment with an ultrahigh non-linearity is useful to support the fwm. in this paper, the experimental set-upof compact fiber ring laser based different lengths of nonlinear bismuth- erbium doped fiber (bi-edf, 181 and215 cm) is employed by using four-wave mixing (fwm) method. these two gain nonlinear media have beensuccessfully used to stabilize a dual-wavelength fiber laser with and without nonlinear photonic crystal fiber(pcf) at room temperature through the degenerate four-wave mixing effect for γ and n2 estimation of non-linearparameters and fwm efficiency of optical fiber. the exclusive and practical benefits of using the high non-linearbismuth-erbium doped fiber (bi-edf) in implementing a fwm applications for non-linear pcf parameters areexperimentally demonstrated. besides, the fwm effect can be also employed for signal amplification, phaseconjugation, wavelength conversion ,and high-speed optical switching. coupled interaction of bi-edf and pcffiber in fwm scattering explain the unique feature of the proposed configuration.