title: All-fiber spot-size transformer for efficient free-space optical interconnecting devices.
abstract: A new concatenated configuration of optical fibers is proposed to improve misalignment tolerance and working distance in a free-space optical interconnection. The structure is composed of three segments: a thermally expanded core fiber, a coreless silica fiber, and a claddingless graded-index fiber. A numerical analysis for the design of each fiber segment is performed completely, and the device characteristics are experimentally evaluated in terms of the tolerances for a 1-dB coupling-loss increment against longitudinal, transverse, and angular misalignments.
authors.affiliation: Department of Information and Communications, Gwangju Institute of Science and Technology, 1 Oryong-dong, Puk-ku, Gwangju, 500-712, Korea.
authors.forename: Kyung-Rok
authors.initials: KR
authors.lastname: Kim
authors.forename: Kyunghwan
authors.initials: K
authors.lastname: Oh