Tailored terahertz radiation
AssigneeRamot at Tel-Aviv University Ltd.
InventorsTal Ellenbogen, Shay Keren-Zur
Life of this patent
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Abstract
Apparatus for generating THz (terahertz) radiation, the apparatus comprising: a substrate; a planar array of asymmetric point antennas formed on the substrate and excitable by a pump pulse of radiation to radiate THz radiation the point antennas having characteristic dimensions substantially smaller than wavelengths of the radiated THz; wherein the array comprises point antennas aligned in different directions.
Claims20
Apparatus for generating THz (terahertz) radiation, the apparatus comprising:
- a substrate;
- a planar array of asymmetric point antennas formed on the substrate and excitable by a pump pulse of radiation to radiate THz radiation, the point antennas having characteristic dimensions substantially smaller than wavelengths of the radiated THz;
- wherein
- the array comprises point antennas aligned in different directions.
A method of providing a non-linear metasurface (NLM) comprising an array of point antennas excitable by a pump pulse of radiation to radiate THz radiation of a given spatiotemporal configuration to a far field of the NLM, the method comprising:
- determining a first Fourier transform equal to a Fourier transform of the spatiotemporal THz radiation for a time shift to equal to a time it takes light to propagate from the NLM to a location having coordinates (x,z) where z is a distance along an optical axis of the NLM and x is a distance perpendicular to z;
- determining a second Fourier transform equal to a Fourier transform of a time dependence of an electric field generated by a point antenna in the array responsive to the pump pulse for the time shift to and a time equal to (x/c)sin θ where θ=arctan(x/z) and c is the speed of light;
- determining a spatial function equal to a quotient equal to the first Fourier transform divided by the second Fourier transform;
- and
- using the spatial function to configure the array.
Dependencies are inferred from the claim text.