title: All-optical logical gates based on pump-induced resonant nonlinearity in an erbium-doped fiber coupler.
abstract: In this paper, we theoretically investigate all-optical logical gates based on the pump-induced resonant nonlinearity in an erbium-doped fiber coupler. The resonant nonlinearity yielded by the optical transitions between the (4)I(15/2) states and (4)I(13/2) states in Er(3+) induces the refractive index to change, which leads to switching between two output ports. First, we do a study on the switching performance, and calculate the extinction ratio (Xratio) of the device. Second, using the Xratio, we obtain the truth tables of the device. The results reveal that compared with other undoped nonlinear couplers, the erbium-doped fiber coupler can drop the switching threshold power. We also obtain different logic gates and logic operations in the cases of the same phase and different phase of two initial signals by changing the pump power.
authors.forename: Qiliang
authors.initials: Q
authors.lastname: Li
authors.forename: Zhen
authors.initials: Z
authors.lastname: Zhang
authors.forename: Dongqiang
authors.initials: D
authors.lastname: Li
authors.forename: Mengyun
authors.initials: M
authors.lastname: Zhu
authors.forename: Xianghong
authors.initials: X
authors.lastname: Tang
authors.forename: Shuqin
authors.initials: S
authors.lastname: Li