Patent ID: 6856752

Claim:
An optical attenuator device selectively operable in a non-actuated state and an actuated state, comprising: a waveguide for guiding optical energy, the waveguide having an input section coupled to an intermediate section, said intermediate section having reduced confinement of the optical energy relative to said input section, said intermediate section having a core and a cladding bounding said core, said core and cladding having matched thermo-optic coefficients, said core having a refractive index that is less than a refractive index of a core of said input section and greater than or equal to a refractive index of said cladding; and a thermal source, disposed above said intermediate section, for generating a temperature gradient within a portion of said intermediate section along a vertical axis thereof when said device is in said actuated state, said temperature gradient being sufficient to alter a refractive index profile within said intermediate section such that a portion of said optical energy is deflected downwardly and extracted from said intermediate section.