DEVICE FOR EXCITATION OF FAR-REACHING PLASMON MODE OF PLASMON WAVEGUIDE Russian patent published in 2019 - IPC G02B6/00 

FIELD: physics.

SUBSTANCE: invention relates to plasmon integrated optics and can be used in designing integrated circuits for various purposes based on plasmon waveguides with a far-reaching plasmon mode. Technical result is achieved due to combined use of horn and grate. When exciting laser beam slots fall onto grating due to diffraction on periodic grating, plasmon modes are excited in layered metal-dielectric-dielectric system or metal-dielectric on one- or two-layer dielectric substrate corresponding to structure of considered excited waveguide. At that, both far-reaching plasmon modes and short-traveling plasmonic modes are excited. Latter are attenuated at a small distance of less than several periods of the grid, while the first ones with relatively small losses propagate at distances of the order of the dimensions of the horn in the plane of the substrate, mainly in the direction perpendicular to the slots. For the most efficient excitation of far-reaching plasmon modes in the above layered system, a horn is required in case the exciting beam falls along the normal to the substrate plane, so that the condition D=λ/n_pl, where D is a period of the array of slots, λ is operating wavelength, n_pl is an effective refractive index of a far-reaching plasmon mode in said layered system, periodically modulated by a grid with slots. Slots are made only through metal layer and overlying dielectric layers and do not affect underlying dielectric layers. Horn serves for focusing of far-reaching plasmon modes excited in said layered system due to diffraction on grating of slots into aperture of plasmon waveguide.

EFFECT: efficient excitation by an incident laser beam of a far-reaching plasmon mode in a plasmon waveguide in the form of a thin metal strip of finite width between dielectric strips of the same width on a single- or double-layer dielectric substrate.

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