Abstract: A method for producing a ridge optical waveguide having low coupling losses between the ridge optical waveguide and an optical fiber includes forming on the surface of a dielectric substrate an optical waveguide having a first end and a second end opposite the first end; cutting out two parallel recesses spaced apart by a distance wr on the surface of the dielectric substrate to form a rigid optical waveguide with an increased width (wr) between the two recesses. The recesses are cut such that the depth of each recess changes continuously and gradually between a zero depth at the height of the first end of the optical waveguide and a maximum depth (Hm) at a pre-determined distance (Ip) from the first end.

Abstract: A method for producing a ridge optical waveguide having low coupling losses between the ridge optical waveguide and an optical fibre includes forming on the surface of a dielectric substrate an optical waveguide having a first end and a second end opposite the first end; cutting out two parallel recesses spaced apart by a distance wr on the surface of the dielectric substrate to form a rigid optical waveguide with an increased width (wr) between the two recesses. The recesses are cut such that the depth of each recess changes continuously and gradually between a zero depth at the height of the first end of the optical waveguide and a maximum depth (Hm) at a pre-determined distance (Ip) from the first end.

Abstract: A bulk wave piezoelectric resonator operating at a predetermined frequency includes a substrate block, having a plane face, a first thickness and consisting of a first material, a resonant plate having a length, width and second thickness, and consisting of a second piezoelectric material, first and second metal electrodes at least partly covering the resonant plate on each side and partly facing each other. The resonant plate is fixed perpendicularly in the vicinity of the plane face of the substrate block so that the width of the resonant plate and the first thickness of the substrate block have the same direction, and the first material, the second material, the first thickness of the block of substrate, the length, the width, the second thickness of the resonant plate are configured for trapping bulk waves at the operating frequency of the resonator and for producing a plane-plane type bulk wave piezoelectric resonator.

Abstract: A piezoelectric and ferroelectric bulk wave transducer operating at a predetermined frequency includes a block of substrate, having a first thickness and in a first material, and a piezoelectric and ferroelectric transduction plate, having a length, a width and a second thickness, and in a second piezoelectric material, first and second metal electrodes covering the plate in the direction of the length thereof. The plate has first and second ferroelectric domains with alternating polarizations, distributed along the length of the plate according to a periodic pattern of pitch. The plate is attached perpendicularly to the block so that the width of the plate and the first thickness of the block are the same direction. The first and second material, the first thickness of the block, the length, the width, the second thickness, the pitch of the plate are configured for generating and trapping bulk waves at the operating frequency of the transducer, guided between both electrodes.

Abstract: A piezoelectric and ferroelectric bulk wave transducer operating at a predetermined frequency includes a block of substrate, having a first thickness and in a first material, and a piezoelectric and ferroelectric transduction plate, having a length, a width and a second thickness, and in a second piezoelectric material, first and second metal electrodes covering the plate in the direction of the length thereof. The plate has first and second ferroelectric domains with alternating polarizations, distributed along the length of the plate according to a periodic pattern of pitch. The plate is attached perpendicularly to the block so that the width of the plate and the first thickness of the block are the same direction. The first and second material, the first thickness of the block, the length, the width, the second thickness, the pitch of the plate are configured for generating and trapping bulk waves at the operating frequency of the transducer, guided between both electrodes.

Abstract: A bulk wave piezoelectric resonator operating at a predetermined frequency includes a substrate block, having a plane face, a first thickness and consisting of a first material, a resonant plate having a length, width and second thickness, and consisting of a second piezoelectric material, first and second metal electrodes at least partly covering the resonant plate on each side and partly facing each other. The resonant plate is fixed perpendicularly in the vicinity of the plane face of the substrate block so that the width of the resonant plate and the first thickness of the substrate block have the same direction, and the first material, the second material, the first thickness of the block of substrate, the length, the width, the second thickness of the resonant plate are configured for trapping bulk waves at the operating frequency of the resonator and for producing a plane-plane type bulk wave piezoelectric resonator.