OPTICAL FIBER FOR OPTICAL FIBER COUPLER AND OPTICAL FIBER COUPLER

摘要

Provided are an optical fiber that can be easily manufactured and can be used for an optical fiber coupler applicable to short wavelength bands, and an optical fiber coupler using the optical fiber. The optical fiber (3) has a pure silica core (9) and a clad (10) formed around the pure silica core (9). In the optical fiber (3), the distribution of refractive index of the clad (10) is uniform. The optical fiber coupler has an optically coupled section formed by melting and extending those portions of the optical fiber (3) and an optical fiber same as the optical fiber (3) which portions are used for optical coupling.