Quasi Slanted Fiber Bragg Grating Multiple Series Fiber Bragg Grating Optical Fiber Type Coupler and Optical Connector

摘要

An optical fiber (4) having a clad diameter of 125 mum is made by adding Ge to a core (41) having a core diameter of 8 mum and a relative index difference of 0.3% and two refractive index grating parts (41a, 41b) having a slant angle of 2° are formed in series in the optical fiber (4) by a phase mask method using KrF excimer laser (lambda=248 nm). The central period (2Lambda) of the phase mask of a chirped grating is 1140 nm, the chirp rate (C) of the period is 1.2 nm/mm, the length (G) of the first and second index grating parts (41a, 41b) is 8 mm, the effective refractive index of the first and second index grating parts (41a, 41b) is 1.447, the refractive index modulation is 3x10-3, and the gap between the first and second index grating parts (41a, 41b) is 1 mm.