OPTICAL WAVEGUIDE, ITS MANUFACTURING METHOD AND OPTICAL MODULE

摘要

PROBLEM TO BE SOLVED: To reduce reflectivity in an end surface of an optical fiber. SOLUTION: Cyclic structure 2 is formed in the end surface of the low end surface reflection optical fiber 1. In cyclic structure 2, a large number of fine pyramidal projections 2a are arranged in a surface shape at equal intervals, and the arrangement interval of adjacent fine projections 2a is smaller than a wavelength of light propagating the inside of the optical fiber 1. Thus, cyclic structure 2 being the end surface of the optical fiber 1 is equivalent to structure in which a refractive index is continuously changed from the end surface toward the inside of the optical fiber 1, and the reflection of light is not generated. Thus, even if light is made incident on the end surface (cyclic structure 2) of the low end surface reflection optical fiber 1, light is not reflected and light is efficiently coupled.