Patent ID: 6697541
Filing Date: 2004-02-24
Classification: G02B

Abstract:
An amplitude tunable filter comprising:a waveguide including a core and cladding that guide a light beam having a range of wavelengths along the core and an overcladding positioned directly over and in contact with at least a portion of said cladding; at least one coupler that couples at least time band of the wavelengths from the core into the cladding, the one band having a central wavelength; wherein said overcladding is in contact with at least a portion of the cladding that is positioned over said at least one coupler, said overcladding having a refractive index that is higher than a refractive index of the cladding; the refractive index of the overcladding being subject to change by an external control; and a controller that adjusts the refractive index of the overcladding within a range that is higher than the refractive index of the cladding to vary an amplitude of the central wavelength of the band.