Peripheral surface-emitting linear light guide and method for manufacturing the same

Abstract

A peripheral surface-emitting linear light guide is provided with an optical fiber including a core, an outer peripheral surface of which is exposed from a cladding at one end in a longitudinal direction, and a light-scattering member that covers an entire periphery of the outer peripheral surface of the core in an exposed portion over a predetermined axial length range. The light emitted from the outer peripheral surface of the core is scattered and radiated by the light-scattering member. The light-scattering member includes a light transmissive base material having a higher refractive index than the core and light-scattering particles that scatter the light incident on the base material, and the light-scattering particles are dispersed and mixed in a certain proportion throughout the base material. At least a portion of the light-scattering member in the longitudinal direction is an incremental portion whose thickness increases gradually toward a tip side of the core.