The invention provides an
optical fiber with high reliability, sealing method for
optical fiber end face, connection structure of
optical fiber, and optical connector. The porus optical
fiber (50) of the invention is formed by a
solid core (11), a clad (12) formed around the core (11), a plurality of holes (13) being formed in the clad with
refractive index being 1, and a hardening resin (15) filled in the holes (13) of the optical
fiber end face (14). The hardening resin (15) if filled around the optical
fiber end face (14) of the plurality of holes (13) and is hardened; the hardening resin (15) having a
moisture permeability equal to or less than 0.5 g / cm2.24 hr, or the
bonding strength with the glass is 5MPa and the
hardness after hardening is the character over 50 expressing by
Shore D
hardness.