title: Broad-bandwidth, reversible, and high-contrast-ratio optical diode.
abstract: Fano resonance is widely used to realize high-contrast nonreciprocal transmission. However, resonance-enhanced all-optical diodes (AOD) are bandwidth-limited, and their transmission rates are normally low, which restricts realistic application. In this Letter, we analytically and numerically demonstrate that this limitation can be overcome once multistability of cascaded nonlinear cavities is appropriately excited. By precisely molding the transiting of the signal light between multistable states, a high-contrast-ratio, high-unidirectional-transmission-rate, and reversal-controllable AOD is achieved with a bandwidth over 2.4 nm, which is about two orders of magnitude wider than the reported results obtained by other methods based on Fano resonances. This approach may pave the way for dynamic control of on-chip all-optical information processing.
authors.forename: Chao
authors.initials: C
authors.lastname: Li
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.forename: Jun-Fang
authors.initials: JF
authors.lastname: Wu