Optical fiber with fresnel diffraction

US7379645B2 · kind B2 · utility

Assignees

• The University of Melbourne · AU
• The University of Sydney · AU

Inventors

• John Canning · Sydney, AU
• Kristy Lee Sommer · Calle de la Era, AU
• Shane Huntington · Melbourne, AU

Key dates

• Filing date: Jan 18, 2002
• Grant date: May 27, 2008
• Expiry date: Feb 12, 2023

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B6/03688
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

An optical fiber being optically transmissive at a predetermined wavelength of light λ and comprising a plurality of coaxial layers. Each layer having an optical path length that varies radially, the coaxial layers being arranged to give the fiber a refractive index profile which, in use, causes sufficient Fresnel diffraction of the light such that it is guided in the fiber. The refractive index of a cladding region (60) is intermittently suppressed by controlling heating of the preform tube, thus forming a chirped saw-tooth profile (70). The optical fiber may include a lens. In this case, each of the layers has an optical path length that increases gradually outwardly by substantially n×λ/2 (n: integer).