Anti-resonant hollow core optical fiber

Abstract

An anti-resonant hollow core optical fiber includes an outer cladding having a pipe shape, a plurality of inner cladding elements each having a pipe shape, the plurality of inner cladding elements being in contact with an inner wall surface of the outer cladding, and a coating layer configured to cover the outer cladding. A space surrounded by the plurality of inner cladding elements is a core region. The coating layer includes a primary resin layer and a secondary resin layer covering an outer periphery of the primary resin layer. The secondary resin layer has an average linear expansion coefficient of 10×10−5 [/° C.] or less at 20° C. to 30° C., and the secondary resin layer has an average linear expansion coefficient of 6×10−5 [/° C.] or less at −60° C. to −50° C. The secondary resin layer has an in-situ elastic modulus of 1500 MPa or more.

Dependencies are inferred from the claim text.