Dispersion bistability of a reflective fiber-optic mode converter

A novel nonlinear device based on a reflective fiber-optic LP(01) ? LP(02) mode converter is proposed. The dispersion effect of optical bistability, i.e., the bistability with respect to the input wavelength, is investigated. Our results show that, when the input wavelength shifts to a wavelength shorter than the Bragg wavelength of the fiber's distributed-feedback structure, the threshold of the switching power for the optical bistability can be reduced. In addition, it is shown that both the switch-on and the switch-off threshold powers for a nonlinearity reflective LP(01) ? LP(02) mode converter are much lower than those of a conventional nonlinear fiber Bragg grating reflector.