Variable optical fiber Bragg filter arrangement

摘要

A variable light filtering arrangement (10) includes at least one optical fiber section (11) including a waveguiding core (13), and at least one permanent Bragg grating region (12) in the optical fiber section. The grating region includes a plurality of grating elements constituted by periodic refractive index variations of a predetermined initial periodicity and cumulatively redirecting, of the light launched into the core for guided propagation therein, that having an axial wavelength within a narrow band around a central wavelength that is determined by the periodicity and refractive index variations of the grating elements. At least one of the periodicity and refractive index variations of the grating region is controlledly modified in such a manner as to temporarily change the central wavelength within a predetermined wavelength range. <IMAGE>