We report on intensity-dependent switching in lithium niobate directional couplers. Large nonlinear phase shifts that are due to cascading detune the coupling between the coupler branches, which makes all-optical switching possible. Depending on the input intensity, the output could be switched between the cross and the bar coupler branches with a switching ratio of 1:5 and a throughput of 80%.

Ahtract -A computer-aided sjnthesis design procedure is given for nonuniform quadrature directional couplers in inhomogeneous media. A wiggly geometry is employed which effective11 slows the odd-mode phase veloci5 to match the even-mode phase velocity. The wiggly geometry results in improved isolation and increased effective dielectric constant. This technique provides a shorter coupler length ...

In this paper a novel design of all-optical half-subtractor based on nonlinear directional coupler is proposed. By using four waveguides and appropriately adjusting the refractive indices and selecting the proper length of waveguides, halfsubtractor function can be obtained. The operation of this function is simulated by RSoft CAD-Layout (BeamPROP) simulator. The simulation results confirm the ...

This paper presents a novel design of compact contra-directional coupler with high directivity for high-power monitoring in frequency. Microstrip parallel coupled lines are widely used directional couplers; however, they show poor inherently. Their has been improved by many works. However, the suggested approaches often result other limitations, such as weak structure monitoring, or larger size...

A simple waveguide directional coupler is described which uses the split-block type of construction common in millimeter-wave components. The coupler uses an array of metal probes suspended on quartz stand-offs. Depending on the number of coupling elements, the coupling can be in the range 15-30 dB, with typically ± 2 dB variation across the waveguide band, and directivity > 10 dB. The coupler,...

USA TEL: (1) 631 231-1700 • INT’L TEL: (1) 631 231-1390 • FAX (1) 631 231-1711 E-MAIL: [email protected] • www.nardamicrowave.com In today’s microwave practice, the directional coupler has become a virtually indispensable measurement tool. It provides a simple, convenient, accurate means for sampling microwave energy without moving parts and without the need for adjustments. Unlike other met...