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Four section of thematic supplementals

This review paper summarizes our previous findings regarding propagation characteristics of band-gap temporal solitons in photonic crystal waveguides with Kerr-type nonlinearity and a realization of functional and easily scalable all-optical NOT, AND and NAND logic gates. The proposed structure consists of a planar air-hole type photonic crystal in crystalline silicon as the nonlinear background material. A main advantage of proposing the gap-soliton as a signal carrier is that, by operating in the true time-domain, the temporal soliton maintains a stable pulse envelope during each logical operation. Hence, multiple concatenated all-optical logic gates can be easily realized paving the way to multiple-input ultrafast full-optical digital signal processing. In the suggested setup, due to the gap-soliton features, there is no need to amplify the output signal after each operation which can be directly used as a new input signal for another logical operation. The efficiency of the proposed logic gates as well as their scalability is validated using our original rigorous theoretical formalism confirmed by full-wave computational electromagnetics. CA Extern

A functional dielectric post-wallwaveguide (PWW) and a PWW-based band-pass filterthat is formed by introducing specific arrangements ofadditional dielectric posts in the guiding region arenumerically analyzed. In this preliminary study, thecomplex wavenumber of the dielectric PWW composedof dielectric rods as wall elements is rigorouslycalculated using our highly efficient full-wave formalismbased on the lattice sums technique. Structural parame-ters of the dielectric PWW are properly chosen using acombination of our full-wave formalism, and a breedergenetic algorithm is employed as a global searchheuristic to achieve a strong confinement of theelectromagnetic fields with a relatively smaller numberof layers in the lateral direction aiming at a realization ofa compact functional device within the desired frequencyrange. After the structural parameters of the PWW aredefined, a functional band-pass filter is realized. The S-parameters of the filter are calculated using the CST 3DEM simulation tool. It is expected that this study will findpractical applications in device integration at millimeter-wave and terahertz frequencies—those at which metalrods used, for example, in conventional substrate-integrated waveguide schemes become too lossy andthus impair their guiding properties.

International audience

http://www.jpier.org/PIER/pier.php?paper=17010704

An accurate formulation to the problem of electromagnetic scattering by the multielements periodic grating of circular cylinders and dielectric slab is presented. The dielectric cylinders are assumed to have different radii and geometrical locations per unit cell and the dielectric slab is located apart from the periodic grating. Applying the boundary conditions and using the additional theorem for the cylindrical functions and the projection method, an infinite system of linear equations for the unknown coefficients of the multipole spectra is obtained. This system of equations is solved by the reduction method and the analytical expressions for both transmission and reflection coefficients are derived by using the relationship between the diffracted spectra and the multipole spectra. The numerical examples demonstrate the multiple scattering effects between the cylindrical elements of the grating and the slab boundaries on the frequency response in the transmission coefficient. It is shown that the frequency response could be controllable by properly adjusting the geometrical parameters of the dielectric slab.