Resonator-based optical circulators are fundamentally bandwidth-limited by their quality factors. We propose a new type of circulator based on directional coupling between one-way photonic chiral edge states and conventional two-way waveguides. The operational bandwidth of such circulators is tied to the bandwidth of the directional waveguide coupler and has the potential for simultaneous broad...

Asymmetric directional coupling between a hybrid plasmonic waveguide with subwavelength field confinement and a conventional dielectric waveguide is investigated. The proposed hybrid coupler features short coupling length, high coupling efficiency, high extinction ratio, and low insertion loss; it can also be integrated into a silicon-based platform. This coupler can be potentially adopted for ...

We report all-optical switching of 100-fsec pulses in a fused-quartz dual-core-fiber directional coupler. The length of the device is 0.5 cm, and the switching power is 32 kW. Pulses are routed to either of two separate fiber guides, depending on the input power. Measurements of pulse reshaping by the nonlinear coupler provide compelling evidence of the device's ability to response on a femotos...

Polymer based electro-optic modulators have shown great potentials in high frequency analog optical links. Existing commercial LiNibO3 Mach-Zehnder modulators have intrinsic drawbacks in linearity to provide high fidelity communication. In this paper, we present the design, fabrication and characterization of a traveling wave directional coupler modulator based on electro-optic polymer, which i...