Broadband microwave waveguide modulator for infrared lasers

Claim 1

A broadband microwave waveguide modulator for phase modulating infrared laser signals provided by a laser source to a guided laser propagation path in the modulator, in response to microwave modulation signals presented from a microwave signal source, comprising: a monolithic thin-film optical waveguide structure of electrooptic material having two mutally parallel sides of substantially equal length and width, including a multi-level first side and a planar second side, said first side having major and minor surfaces each parallel to said second side and displaced therefrom by a minimum dimension and by a maximum dimension respectively, said minor surface comprising the upper surface of a raised ridge projecting above said major surface and extending longitudinally along a central portion of said first side, said ridge having both length and width smaller than that of said first side, said ridge and the portion of said structure between said ridge and said second side defining a guided laser propagation path; optical couplers, one disposed at each end of said raised ridge on said first side, for coupling the infrared radiation from the laser source through said guided laser propagation path in a selected TE propagation mode; and a pair of microwave electrodes, one disposed on said minor surface and co-extensive with said ridge and one disposed on said second side surface co-extensive with that portion bounding said guided laser propagation path, said electrodes providing, in response to modulation signals from the microwave signal source, a microwave modulated electric field in said guided laser propagation path for phase modulating the infrared radiation therein.