Radiatively coupled corrugated waveguides

A new system of radiatively coupled waveguides is proposed. The coupling between the waveguides is due to diffraction of light by their corrugated surfaces. The dispersion curves and the dependence of the coupling length on the structure parameters are calculated. The optimal distance between the waveguides that ensures the maximum degree of transfer of radiation is determined. It is shown that in this case the coupling length has its maximum value equal to π/2α_rad, where α_rad is the coefficient representing radiative losses in a single waveguide.