Patent ID: 8687931
Filing Date: 2014-04-01
Classification: G02B

Abstract:
1. An optical fiber comprising: a core region extending along an optical axis; and a cladding region provided on an outer periphery of the core region, wherein the cladding region comprises: an optical cladding, as a region which affects transmission characteristics of light propagating through the core region, provided on the outer periphery of the core region; and a physical cladding, as a region which does not affect transmission characteristics of light propagating through the core region, provided on an outer periphery of the optical cladding, wherein the physical cladding includes a leakage reduction portion for suppressing the propagation, outside the cladding region of leaked light which has arrived via the optical cladding from the core region, wherein, by causing the leaked light arriving from the core region to be deflected, the leakage reduction portion reduces the light quantity of leaked light which propagates outside the cladding region, and wherein the leakage reduction portion has a higher refractive index than those of the optical cladding and the physical cladding from which the leakage reduction portion is excluded, whereby the leaked light, which has arrived from the core region, propagates through the leakage reduction portion.