FIBER GRATING AND MANUFACTURING DEVICE OF THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a fiber grating in which group delay ripple characteristics causing a problem for dispersion compensation in optical fiber transmission are suppressed. SOLUTION: In the refractive index distribution of the fiber grating in a longitudinal direction of the grating, the average refractive index is controlled to be constant in a grating forming region and is gradually decreased from the boundary between the grating forming region and an outer region of the grating forming region. This can suppress ripples in the group delay characteristics of the fiber grating due to unnecessary resonance of an etalon at both ends of the grating forming region and improve the linearity of the group delay characteristics. COPYRIGHT: (C)2007,JPO&INPIT