Abstract: An object of the present invention is to provide a manufacturing method of an optical waveguide element whose DC drift is suppressed, and to provide a manufacturing method of an optical waveguide element, capable of adjusting DC drift in the middle of manufacturing processes so as to improve a fabrication yield. The method of manufacturing an optical waveguide element comprises a step of forming an optical waveguide in a substrate having an electro-optic effect, a step of forming a buffer layer, and a step of forming an electrode, in which one stage or a plurality of stages of an interface diffusion layer heat adjustment step (S1, S2) for adjusting a concentration distribution of a specific substance in the buffer layer by heating is included after the buffer layer is formed.

Abstract: An object of the present invention is to provide a manufacturing method of an optical waveguide element whose DC drift is suppressed, and to provide a manufacturing method of an optical waveguide element, capable of adjusting DC drift in the middle of manufacturing processes so as to improve a fabrication yield. The method of manufacturing an optical waveguide element comprises a step of forming an optical waveguide in a substrate having an electro-optic effect, a step of forming a buffer layer, and a step of forming an electrode, in which one stage or a plurality of stages of an interface diffusion layer heat adjustment step (S1, S2) for adjusting a concentration distribution of a specific substance in the buffer layer by heating is included after the buffer layer is formed.

Abstract: An optical waveguide device that uses a thin substrate having an electro-optical effect and a thickness of 10 ?m or less, in which slab propagation light that is reflected from an end face of the device is removed and thus deterioration in an operational characteristic is suppressed. The optical waveguide device includes: a thin substrate which has an electro-optical effect and thickness of 10 ?m or less, and in which an optical waveguide is formed; and a supporting substrate that is adhered to the thin substrate through an adhesion layer. An antireflective film is formed on a part of a side surface of the optical waveguide device.

Abstract: An object of present invention is to provide an optical waveguide element that suppresses damage to an optical waveguide element by a pyroelectric effect due to a reinforcement substrate. Provided is an optical waveguide element in which an optical waveguide substrate is bonded to a reinforcement substrate having an electro-optical effect via an adhesive layer, the optical waveguide substrate having an optical waveguide formed on a substrate having the electro-optical effect and having a thickness of 30 ?m or less, wherein a semiconductor layer is provided on a surface of the adhesive layer side of the reinforcement substrate.

Abstract: It is an object of the invention to provide a light modulator using a thin plate having a thickness of 20 ?m or less and capable of stably holding a conductive film suppressing troubles such as resonance phenomenon of microwaves in a substrate and pyro-electric phenomenon and to provide a method of fabricating the light modulator. The light modulator includes: a thin plate (10) formed of a material having an electro-optic effect and having a thickness of 20 ?m or less; a light waveguide (11) formed on the front or rear surface of the thin plate; and modulation electrodes (13, 14) formed on the front surface of the thin plate to modulate light passing through the light waveguide. The light modulator further includes a reinforcing plate (16) bonded to the rear surface of the thin plate and a conductive film (17) continuously formed in the range from the side surface of the thin plate to the side surface of the reinforcing plate.

Abstract: An optical modulator is provided. The optical modulator includes a thin plate made of an electrooptic material and having a thickness of 20 ?m or less, an optical waveguide formed on a top or bottom surface of the thin plate, and a modulation electrode formed on the top surface of the thin plate to modulate light passing through the optical waveguide, wherein, in a shape of the thin plate, a width of the thin plate at an optical input portion or optical output portion of the optical waveguide is two time or less the thickness of the thin plate.

Abstract: It is an object of the invention to provide a light modulator using a thin plate having a thickness of 20 ?m or less and capable of stably holding a conductive film suppressing troubles such as resonance phenomenon of microwaves in a substrate and pyro-electric phenomenon and to provide a method of fabricating the light modulator. The light modulator includes: a thin plate (10) formed of a material having an electro-optic effect and having a thickness of 20 ?m or less; a light waveguide (11) formed on the front or rear surface of the thin plate; and modulation electrodes (13, 14) formed on the front surface of the thin plate to modulate light passing through the light waveguide. The light modulator further includes a reinforcing plate (16) bonded to the rear surface of the thin plate and a conductive film (17) continuously formed in the range from the side surface of the thin plate to the side surface of the reinforcing plate.

Abstract: An optical modulator capable of efficiently separating radiation light and propagation light from each other or removing the radiation light in the optical modulator to suppress loss of the optical modulator and deterioration of an extinction ratio, including a thin plate of a material having an electrooptic effect and a thickness of 20 ?m or less; an optical waveguide formed in a top surface or a bottom surface of the thin plate; and a modulation electrode formed in the top surface of the thin plate to modulate light which propagates in the optical waveguide, the optical waveguide has an optical junction portion in which a plurality of optical waveguide portions are joined together and, for shielding a portion of radiation light radiated from the optical junction portion, a concave portion or through-hole in the thin plate.

Abstract: An optical modulator using a thin plate capable of improving an S/N ratio of an output light is provided. The optical modulator including a thin plate 1 having an electrooptic effect and having a thickness of 20 ?m or less, an optical waveguide 4 formed on a top or bottom surface of the thin plate, and a modulation electrode formed on the top surface of the thin plate to modulate light passing through the optical waveguide, wherein a stray light removing member 10 is disposed within the thin plate or in a vicinity of the thin plate.

Abstract: Provided is an optical modulator capable of efficiently separating radiation light and propagation light from each other or removing the radiation light in the optical modulator to suppress loss of the optical modulator and deterioration of an extinction ratio. In the optical modulator including a thin plate made of a material having an electrooptic effect and having a thickness of 20 ?m or less; an optical waveguide formed in a top surface or a bottom surface of the thin plate; and a modulation electrode which is formed in the top surface of the thin plate to modulate light which propagates in the optical waveguide, the optical waveguide has an optical junction portion in which a plurality of optical waveguide portions are joined together and a shielding means for shielding a portion of radiation light radiated from the optical junction portion.

Abstract: An optical modulator in which stabilized driving is realized over a long time by relaxing stress generated in a recess formed in the surface of a substrate in the optical modulator and controlling deterioration of optical modulation control caused by stress-strain in the substrate including an optical waveguide. The optical modulator comprises a substrate of a material exhibiting electrooptic effect, an optical waveguide (4) provided on the substrate, and control electrodes (20-25) for controlling the phase of light being guided through the optical waveguide characterized in that a recess (12) is provided in the surface of the substrate for forming the control electrodes, and the control electrode (24) being formed on the recess is provided with a stress relaxing means.

Abstract: An optical modulator is provided. The optical modulator includes a thin plate made of an electrooptic material and having a thickness of 20 ?m or less, an optical waveguide formed on a top or bottom surface of the thin plate, and a modulation electrode formed on the top surface of the thin plate to modulate light passing through the optical waveguide, wherein, in a shape of the thin plate, a width of the thin plate at an optical input portion or optical output portion of the optical waveguide is two time or less the thickness of the thin plate.

Abstract: An optical modulator using a thin plate capable of improving an S/N ratio of an output light is provided. The optical modulator including a thin plate 1 having an electrooptic effect and having a thickness of 20 ?m or less, an optical waveguide 4 formed on a top or bottom surface of the thin plate, and a modulation electrode formed on the top surface of the thin plate to modulate light passing through the optical waveguide, wherein a stray light removing member 10 is disposed within the thin plate or in a vicinity of the thin plate.

Abstract: An optical modulator in which stabilized driving is realized over a long time by relaxing stress generated in a recess formed in the surface of a substrate in the optical modulator and controlling deterioration of optical modulation control caused by stress-strain in the substrate including an optical waveguide. The optical modulator comprises a substrate of a material exhibiting electrooptic effect, an optical waveguide (4) provided on the substrate, and control electrodes (20-25) for controlling the phase of light being guided through the optical waveguide characterized in that a recess (12) is provided in the surface of the substrate for forming the control electrodes, and the control electrode (24) being formed on the recess is provided with a stress relaxing means.

Abstract: The present invention intends to control DC drift phenomenon in a light control element having ridge structure, and to provide a light control element with high drive stability in a large area. The present invention has character that, in a light control element being equipped with a base plate that has an electrooptic effect, an optical guide and an electrode for modulation that are formed on said base plate, which has ridge structure, an anti-DC drift layer is installed on the surface of the above mentioned base plate where the optical guide is formed, and annealing treatment is performed after ridge processing.

Abstract: There is provided a high performance optical waveguide type optical modulator with excellent long term reliability, in which contamination of the buffer layer in a forming process of a signal field adjustment region on the buffer layer by a lift-off method or an etching method, is prevented and DC drift thus suppressed.

Abstract: The present invention intends to control DC drift phenomenon in a light control element having ridge structure, and to provide a light control element with high drive stability in a large area. The present invention has character that, in a light control element being equipped with a base plate that has an electrooptic effect, an optical guide and an electrode for modulation that are formed on said base plate, which has ridge structure, an anti-DC drift layer is installed on the surface of the above mentioned base plate where the optical guide is formed, and annealing treatment is performed after ridge processing.

Abstract: There is provided a high performance optical waveguide type optical modulator with excellent long term reliability, in which contamination of the buffer layer in a forming process of a signal field adjustment region on the buffer layer by a lift-off method or an etching method, is prevented and DC drift thus suppressed.

Abstract: An optical modulator including a substrate made of lithium niobate having an electrooptical effect, first and second optical waveguides formed in the substrate by effecting a thermal diffusion of titanium into a surface of the substrate, a buffer layer formed on the surface of the substrate, a hot electrode provided on the buffer layer and having a width W.sub.e not larger than a width W.sub.f of the optical waveguide, first and second ground electrodes provided on the buffer layer such that these ground electrodes are symmetrical with respect to the hot electrode, and an electric field adjusting region having a width not smaller than that of the hot electrode is provided between the buffer layer and the hot electrode. First and second ground side electric field adjusting main- and sub-regions may be provided between the buffer layer and the first and second ground electrodes, respectively.

Abstract: An optical waveguide device usable as an optical wave-modulator and having a reduced DC drift includes a LiNbO.sub.3 substrate, an optical waveguide formed in a front surface portion of the substrate, a dielectric layer covering the front surface of the substrate and the optical waveguide surface, and an electrode system arranged on the dielectric layer, the dielectric layer comprising a matrix component consisting of an amorphous SiO.sub.2 and a doping element component consisting of Li and/or Nb; and having a refractive index lower than that of the amorphous SiO.sub.2 matrix free from the doping element component.