Patent ID: 7035515

Claim:
An optical waveguide device, comprising: a length of fiber including a monomode core having a refractive index of n co , a photosensitivity of S co and a radius R co ; an internal cladding with a refractive index of n cl , a photosensitivity of S cl and a radius of R cl ; an outer cladding surrounding the internal cladding with a refractive index that allows the existence of multiple cladding modes; and a slanted Bragg grating with an effective tilt angle of θ written in the core and inner cladding of the optical waveguide, coupling the fundamental mode into several cladding modes; wherein: the refractive index of the internal cladding is less than the refractive index of the outer cladding, the photosensitivity of the internal cladding is greater than the photosensitivity of the core, R cl ≦2.5 R co , and the optical waveguide device is configured to produce an asymmetric transmission spectrum, and the photosensitivity of the internal cladding is constant between the core and the outer cladding.