Patent ID: 6438293
Filing Date: 2002-08-20
Classification: G02F

Abstract:
An optical signal device for use with a multiple wavelength light signal, the optical device comprising:a) a substrate; b) a pair of first and second spaced apart cladding layers having at least similar refractive indices; c) a core layer including a waveguide or a pair of opposed waveguides positioned between the pair of cladding layers having a refractive index greater than the refractive indices of the first and second cladding layers such that the difference between the refractive indices of the core layer and the cladding layers enables the multiple wavelength light signal to pass through the device in a single mode; d) a grating region present in each of the cladding layers and the core layer, the grating forming a filter element, the filter element causing a single wavelength of light of the multiple wavelength light signal to be segregated therefrom; and e) a tuning apparatus for varying the refractive index of at least the core layer to thereby control the wavelength of the light which is to be segregated from the multiple wavelength light signal, wherein the optical signal device has an input port for inputting the multiple wavelength light signal, a drop port for dropping the single wavelength of light segregated from the multiple wavelength light signal, a pass port for outputting the remaining wavelengths of the multiple wavelength light signal, and an add port for adding to the remaining wavelengths an optical signal having a wavelength equal to the dropped wavelength.