Discrete soliton diode induced by synthetic gauge phase

We demonstrate the nonreciprocal dynamics of discrete solitons (DSs) induced by a uniform synthetic gauge phase (SGP) in one-dimensional waveguide array. The SGP is embedded into the coupling constant between the waveguides, which provides a directional momentum to the propagating fields and creates a nonreciprocal for the system. When a kicked Gaussian wave packet propagates through the waveguide arrays, diode effects are formed. Dependence between the diode effect and the SGP is studied. We found that the threshold of the reverse breakdown of this optical diode exhibits a perfect linear dependence against the SGP, and an extremely high diode quality can be achieved when the initial phase tilt exactly compensates the initial momentum provided by the SGP. Moreover, the direction of the diode can be switched by the direction of the SGP, which brings additional freedom to control the one-way propagation of the DSs. Our finding may have potential application to realizing new devices in high-speed all-optical communications.