Patent attributes
Disclosed is an ultralow loss hollow-core antiresonant fiber, which includes an outer layer structure, a hollow-core area and a plurality of closed cavities. The radial section of the inner surface of the outer layer structure is a circle with a first radius. In the circumferential direction of the inner surface of the outer layer structure, the plurality of the closed cavities are spaced from one another and are distributed uniformly and circumferentially. Each closed cavity includes: an outermost wall serving as a first thin wall, and the radial section of the outermost wall is a fan shape or a circle with a second radius. Each closed cavity further includes: second thin walls located in the inner space surrounded by the inner surface of the outermost wall, and the end surfaces of the second thin walls are annular thin-walled structures with thin-walled spacers arranged in the centers.