Patent ID: 8447156
Filing Date: 2013-05-21
Classification: G02B

Abstract:
1. A multi-core optical fiber, comprising: a plurality of core fiber regions in a same cross-section, each of the core fiber regions comprising a core region extending along an optical axis, and a cladding region provided on an outer periphery of the core region; a leakage reduction portion provided on a straight line connecting the core regions in the adjacent core fiber regions, among the plurality of core fiber regions; and a layer provided in the outside of the leakage reduction portion, the layer having a refractive index higher than that of the leakage reduction portion, wherein: the multi-core optical fiber is a silica-based optical fiber, and the leakage reduction portion has a refractive index profile such that a confinement factor of propagating light in a region surrounded by the leakage reduction portion is raised.