Abstract:
An optical waveguide device including an electro-optical crystal substrate having a top surface and a bottom surface; an optical waveguide path formed within a surface of the electro-optical crystal substrate; at least one electrode positioned above the optical waveguide path for applying an electric field to the optical waveguide path; and a silicon titanium oxynitride layer and a connecting layer for interconnecting the silicon titanium oxynitride layer to another surface of the electro-optical crystal substrate that is opposite to the surface in which the optical waveguide path is formed.
Abstract:
A waveguide type optical device includes a lithium niobate substrate, a Ti diffused waveguide formed in the substrate, an electrode formed on the waveguide for applying an electric field to the waveguide, a first buffer layer made of SiO.sub.2 and formed as a film between the electrode and the waveguide, and a second buffer layer made of Si and formed as a film in a region including at least part of the waveguide above the first buffer layer.
Abstract:
The present invention relates to a device for velocity matching between optical and electrical signals in a waveguide structure comprising first waveguiding means for optical signals and second waveguiding means for electrical signals. The cross-section of the waveguide structure varies dielectrically in the direction of the propagation.
Abstract:
An insulating buffer layer of SiO.sub.2 is formed on a substrate of LiNbO.sub.3 crystal in which optical waveguides are formed, and a semiconducting film of Si is formed on the buffer layer. An insulating diffusion suppressing layer of SiO.sub.2 is formed on the semiconducting film, and a pair of electrodes of Au are located on the diffusion suppressing layer. The formation of silicide by solid-phase diffusion of the electrodes into the semiconducting film can be prevented by the diffusion suppressing layer.
Abstract:
In a waveguide-type optical device, two optical waveguides are formed in a substrate of LiNbO.sub.3 or LiTaO.sub.3. On the substrate and the two waveguides, a blocking layer is formed to block a diffusion of Li ions from the substrate. On the blocking layer, a buffer layer made from SiO.sub.2 is formed. Each of the electrodes, from which operation voltages are supplied, covers each coupling part of the two optical waveguides, respectively, via the blocking layer and the buffer layer.
Abstract:
An insulating buffer layer of SiO.sub.2 is formed on a substrate of LiNbO.sub.3 crystal in which optical waveguides are formed, and a semiconducting film of Si is formed on the buffer layer. An insulating diffusion suppressing layer of SiO.sub.2 is formed on the semiconducting film, and a pair of electrodes of Au are located on the diffusion suppressing layer. The formation of silicide by solid-phase diffusion of the electrodes into the semiconducting film can be prevented by the diffusion suppressing layer.
Abstract:
An improved high-speed external optical modulator, modulated by RF waves, which velocity matches the RF waves with the optical waves is disclosed. The apparatus includes a lithium niobate substrate on which is formed an optical waveguide, electrically floating electrodes, a low dielectric buffer layer and electrodes carrying the modulating RF energy.
Abstract:
A TE polarization absorption film is provided on an optical waveguide between an ouput end of the optical waveguide and a directional coupler composed of the optical waveguide and another optical waveguide. In accordance with the presence of the TE polarization absorption film, a difference of output light power between polarization components becomes minimized.
Abstract:
An optical switch for switching light from one leg of an optical circuit to another leg is characterized by an arrangement for altering the index of refraction of one of the legs with respect to the other leg. This results in a disparity in light velocity and a change in phase relationship for the light being propagated through the legs. When the legs are brought into a coupling region, there occurs a predetermined transfer of light from one leg to the other, depending upon the magnitude of the alteration in phase relationship between the light propagated in the legs.