Asymmetric waveguide pair acoustic surface wave switch

Claim 1

An asymmetric waveguide pair switch comprising: a substrate having a major surface; a first dielectric medium disposed on said major surface of said substrate, said first dielectric medium having a first preselected index of refraction and being patterned to define a pair of spaced apart waveguides extending across said major surface of said substrate; each of said pair of waveguides having a preselected propagation constant at which propagation of a signal therethrough can be supported; a second dielectric medium covering said waveguides and having a second index of refraction lower than said preselected index of refraction of said first dielectric medium defining said waveguides; a film of piezoelectric material disposed on said dielectric medium in overlying relation with respect to a portion of said pair of waveguides; surface wave transducer means defined on said film for generating an acoustic surface wave therein to interact with at least one of said pair of waveguides; and the propagation constant of the portion of said one waveguide operably associated with said surface wave transducer means being changeable to a value corresponding to the fundamental mode of propagation of the other waveguide in response to the interaction of said acoustic surface wave therewith such that a signal being propagated through the other waveguide may be switched to said at least one waveguide.