Patent ID: 6321008
Filing Date: 2001-11-20
Classification: G02B

Abstract:
A Bragg grating filter optical waveguide including a first guiding region doped with a material whose refractive index can be modified and a second region around said first region, wherein said Bragg grating is formed in said first region as a quasi-periodic succession of variations of the optical refractive index along the length of said fiber, said grating is inclined relative to a plane perpendicular to the axis of propagation of light in said waveguide; said Bragg grating further includes a variation of said period along the length of said waveguide; said variation of said period is a monotonous variation along the length of said fiber; all or part of said second region is doped with a material having a refractive index that can be modified and said second region is also modified to form a quasi-periodic and inclined longitudinal grating made up of index modifications with the same period and with the same monotonous variation of said period along the length of said waveguide; andwherein said optical waveguide is an optical fiber, said first region is the core of said optical fiber and second region is the cladding of said optical fiber; andwherein an internal part of said fiber has a photosensitivity less than the photosensitivity of a part external to the internal part.