Dispersion profile studies on twin core directional fiber couplers

Twin core nonlinear directional coupler that include loss and dispersion index are examined. The inclusion of loss results in increase of critical power of the coupler while the switching characteristics deteriorate. To compensate for this worse behavior, associated to the loss, we have investigated the effect of the dispersion profile decreasing. We have show that appropriate shaping of the dispersion profile is quite effective to recover, almost completely, the original switching behavior associated to the lossless situation. It is concluded that hyperbole dispersion profile is nearly optimum for recovery of the lossless switching behavior.