We demonstrate that a nonlinear directional coupler with special bending of waveguide axes can be used for all-optical switching of polychromatic light with a very broad spectrum covering all of the visible region. The bandwidth of the suggested device is enhanced five times compared with conventional couplers. Our results suggest novel opportunities for the creation of all-optical logical gate...

Abstract – We propose a new ring resonator side-coupled M-Z interferometer all-optical switch through the pumped nonlinear directional coupler. By controlling pump power P to lead the coupler reflectivity r approaching to 1, the resonator finesse will be enhanced dramatically, and then the minimum switching power in silica-based practice devices can be obtained. As a sample, we use a nonlinear ...

A novel design of all-optical logic gates based on nonlinear slot waveguide couplers is proposed. NOT, OR, and AND logic gates can be realized by simple single optical directional coupler configuration. Strong polarization dependencies of slot waveguides are effectively utilized for realizing polarization-independent optical directional couplers in linear regime and polarization-dependent all-o...

The Zeno effect is investigated for soliton type pulses in a nonlinear directional coupler with dissipation. The effect consists in increase of the coupler transparency with increase of the dissipative losses in one of the arms. It is shown that localized dissipation can lead to switching of solitons between the arms. Power losses accompanying the switching can be fully compensated by using a c...

We suggest a novel scheme for multistep cascaded parametric processes based on a periodically poled nonlinear directional coupler and derive the conditions for simultaneous phase matching of the second-harmonic generation and sum-frequency mixing processes. We predict an efficient wavelength conversion by the cascaded third-harmonic generation from the third optical communication window (1.53-1...

We propose a type of all-optical switch which consists of two periodically modulated nonlinear optical waveguides placed in parallel. Compared to the all-optical switch based on the traditional nonlinear directional coupler without periodic modulation, this all-optical switch has much lower switching threshold power and sharper switching width.

We study, theoretically and experimentally, autoresonant dynamics of optical waves in a spatially chirped nonlinear directional coupler. We show that adiabatic passage through a linear resonance in a weakly coupled light-wave system yields a sharp threshold transition to nonlinear phase locking and amplification to predetermined amplitudes. This constitutes the first observation of autoresonanc...

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...

This Letter reports a nonlinear directional waveguide coupler written by ultrafast laser in gallium lanthanum sulfide chalcogenide glass. The nonlinear waveguide device is tested with laser pulses input in two orthogonal polarizations, and all optical switching at 1040 nm between the two coupled waveguides is observed at a peak fluence of 16 GW/cm2. The spectra and autocorrelation measurement f...

Soliton switching in a nonlinear directional coupler (NLDC) with Kerr nonlinearity and coupling constant dispersion (caused by intermodal dispersion between the symmetric and the anti-symmetric modes of the coupler) is studied using the well-known variational method. Switching characteristics are calculated and discussed. It is shown that the switching characteristics of the Kerr coupler for al...