access icon free Coupling of terahertz radiation to metallic wire using end-fire technique

Coupling of THz radiation at 625 GHz onto a copper wire is demonstrated. The end-fire technique is used in combination with an axicon to excite the azimuthally polarised surface plasmon polaritons on the wire‘s front facet. A small lateral offset of the wire relative to the optical axis is used to achieve significant plasmon excitation. Coupling efficiencies of about 17% were measured. The coupling mechanism is discussed theoretically using the overlap integral and verify plasmonic excitation and propagation by measuring the radiated field at the wire end.

Inspec keywords: surface plasmons; wires; copper; polaritons

Other keywords: surface plasmon polaritons; end-fire technique; frequency 625 GHz; plasmon excitation; terahertz radiation coupling; coupling efficiency; metallic wire; lateral offset; overlap integral

Subjects: Collective excitations (surface states); Polaritons

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