Patent ID: 6701033
Filing Date: 2004-03-02
Classification: G02B,G02F

Abstract:
An optical switch element comprising:a substrate; a plurality of optical waveguides, which mutually intersect at an intersecting part of the waveguides, said optical waveguides being located on said substrate; cladding adjacent to said optical waveguides; an optical wave-guiding member, located near the intersecting part of the optical waveguides, capable of coupling said optical waveguides; a control portion, located above said optical wave-guiding member, operable to effect a state change of said optical wave-guiding member at least between a first state and a second state so as to control the refractive index of said optical wave-guiding member; and a layer having a refractive index lower than the refractive index of said optical wave-guiding member, located between said optical wave-guiding member and said control portion; wherein said optical wave-guiding member, said optical waveguides, and said cladding are formed such that: the refractive index of said optical wave-guiding member in the first state is effectively equal to or greater than the refractive index of said optical waveguides; and the refractive index of said optical wave-guiding member in the second state is effectively equal to the refractive index of said cladding; wherein: said control portion is further operable to apply the state change to said optical waveguides and said cladding; said optical waveguides and said optical wave-guiding member are formed from respective materials that exhibit opposite refractive index change characteristics from one another when the state change is effected; and said cladding and said optical wave-guiding member are formed from respective materials that exhibit opposite refractive index change characteristics from one another when the state change is effected; and wherein said plurality of optical waveguides and said cladding are formed using material and under formation conditions such that the optical waveguides and the cladding exhibit similar refractive index change characteristics and the refractive index characteristics of the optical waveguides and the cladding have a difference that does not depend on temperature, such that the refractive indexes of the optical waveguides, the cladding, and the optical wave-guiding member are not the same at any state.