A radio frequency (RF) waveguide device fabricated by additive manufacturing is provided that includes a RF channel comprising a wall and a RF component comprising an unsupported span extending from the wall of the RF channel. The unsupported span can include at least one unsupported surface extending from the wall at an oblique angle relative to the wall. The RF component formed in this manner with additive manufacturing does not negatively impact the RF performance of the RF waveguide.

A metalens capable of concentrating terahertz waves having a high light concentration efficiency. The metalens includes a first region that has a plurality of microstructures disposed therein to concentrate terahertz waves; and a second region that is a region that surrounds the first region and that is a region different from the first region, in which in a case where terahertz waves having a wavelength of 0.3 mm, a wavelength of 1 mm, and a wavelength of 3 mm are incident, assuming that a wavelength having a highest light concentration efficiency is a wavelength X, a transmittance of the terahertz waves having the wavelength X in the first region is a transmittance T1, and a transmittance of the terahertz waves having the wavelength X in the second region is a transmittance T2, the transmittance T2 is lower than the transmittance T1.

A metalens capable of concentrating terahertz waves having a high light concentration efficiency. The metalens includes a first region that has a plurality of microstructures disposed therein to concentrate terahertz waves; and a second region that is a region that surrounds the first region and that is a region different from the first region, in which in a case where terahertz waves having a wavelength of 0.3 mm, a wavelength of 1 mm, and a wavelength of 3 mm are incident, assuming that a wavelength having a highest light concentration efficiency is a wavelength X, a transmittance of the terahertz waves having the wavelength X in the first region is a transmittance T1, and a transmittance of the terahertz waves having the wavelength X in the second region is a transmittance T2, the transmittance T2 is lower than the transmittance T1.