Simple wide-aperture waveguide coupler for IO acousto-optic processors

A new simple wide-aperture coupler is offered for coupling an optical radiance into and out of a planar optical waveguide. A coupler is a plane-parallel plate with the refractive index (RI) close to RI of an optical waveguide. The air gap between the coupler and the waveguide is formed by the coupler's elastic deformation. A coupler is distinguished by simplicity in fabrication and adjustment, high coupling efficiency (calculating value is 99% for optimal coupler parameters), and high uniformity of the coupler efficiency across the wide input light beam section thanks to the adaptivity to surface waveguide form errors. One expects that such a coupling method may be widely used both in the design of the high-quality hybrid integro- optical processors (especially acousto-optical) and in the laboratory experimental research in integrated optics.