Dielectric waveguide, terahertz circuit and terahertz integrated circuit

A terahertz circuit comprising:

• a first unclad dielectric waveguide;
• a second unclad dielectric waveguide;
• a dielectric substance terahertz circuit connected between the first unclad dielectric waveguide and the second unclad dielectric waveguide;
• a first holding unit configured to hold the first unclad dielectric waveguide;
• a second holding unit configured to hold the second unclad dielectric waveguide;
• a first low-refractive index cladding layer disposed between the first holding unit and the first unclad dielectric waveguide;
• and
• a second low-refractive index cladding layer disposed between the second holding unit and the second unclad dielectric waveguide.

A terahertz integrated circuit comprising:

• a first unclad dielectric waveguide;
• a second unclad dielectric waveguide capable of evanescent coupling to the first unclad dielectric waveguide;
• and
• a holding unit configured to hold the first unclad dielectric waveguide and the second unclad dielectric waveguide, wherein
• the first unclad dielectric waveguide has a first wiring width at a first bent portion, and a second wiring width wider than the first wiring width at a portion different from the first bent portion, wherein
• the second unclad dielectric waveguide comprises periodic lattice points in which a size and a period of holes are gradually increased.