Patent ID: 6282342
Filing Date: 2001-08-28
Classification: G02B,H01S

Abstract:
An optical device for filtering a light signal, said optical device having a tunable spectral response, said optical device comprising:a first optical fiber having a first core and a first cladding with refractive index n.sub.2, said first core includes a first central region having a refractive index n.sub.1 ; anda first fiber coupling regulator integral with said first optical fiber, said first fiber coupling regulator couples the light signal between a first optical path and second optical path and substantially prevents the light signal from coupling into a third optical path;wherein the first fiber coupling regulator includes:a first optical coupler integral to the first optical fiber for coupling the light signal between the first path and the second path and producing a first output signal, wherein the first path is a LP.sub.01 mode of the light signal and the second path is a LP.sub.02 mode of the light signal; anda first coupling inhibitor integral with at least one of said first optical coupler or the first optical fiber, said first coupling inhibitor substantially prevents the light signal from coupling into the third path, wherein the third path is any mode of the light signal higher than said LP.sub.02 mode;wherein the first optical coupler includes a tapered region in the first optical fiber, wherein said tapered region is characterized by a taper ratio defined as a change in a radius of the first optical fiber over a change in a length of said tapered region; andwherein the first optical coupler comprises a trough region disposed in the first core between the first central region and the first cladding, said trough region having a refractive index n.sub.6, wherein n.sub.1 >n.sub.2 >n.sub.6.