Method for producing chirped in-fibre bragg grating

摘要

Disclosed is a method for producing a chirped in-fibre Bragg grating, in which an interval between gratings varies continously depending on a location of the gratings observed along an optical fibre (2), comprising a first step of winding the optical fibre in a spiral groove formed around a conical bobbin (1) which is shaped in a frustrum of a right circular cone having a predetermined vertex angle and a height between predetermined first and second diameters, and a second step of irradiating the optical fibre wound on the conical bobbin with ultraviolet rays (6) at every crossing of the optical fibre with a predetermined number of uniformly distributed generating lines of the conical bobbin, each extending radially on the surface of the conical bobbin from an imaginary vertex thereof, for modifying the refractive index of a core of the optical fibre to form the grating at the every crossing.