Graphene hybrid waveguide stimulation using a photoconductive terahertz generator.

Area of Science:

• Condensed matter physics
• Optoelectronics
• Nanotechnology

Background:

• Terahertz (THz) surface plasmon polariton (SPP) excitation traditionally requires complex phase-matching engineering and THz plane-wave generation.
• Existing methods necessitate optical components like antennas and lenses, increasing setup complexity and reducing power efficiency.

Purpose of the Study:

• To demonstrate a novel and simplified method for exciting THz SPPs in graphene.
• To improve the power efficiency of THz SPP generation by miniaturizing the excitation setup.

Main Methods:

• Direct excitation of THz SPPs in graphene using an 800 nm optical pump.
• Utilizing a photoconductive source for THz generation.
• Eliminating the need for a plane-wave generator and mode-matching components.

Main Results:

• Achieved direct excitation of THz SPPs in graphene.
• Miniaturized the SPP excitation setup significantly.
• Demonstrated improved power efficiency, obtaining an average SPP power of 0.6 mW for 25 mW optical pump power.

Conclusions:

• The developed method offers a more efficient and compact approach for THz SPP excitation in graphene.
• This technique bypasses the conventional requirements for phase-matching and plane-wave generation.
• The improved power efficiency holds promise for various THz applications utilizing graphene-based SPPs.