Sumitomo Osaka Cement Co., Ltd.

Naitonal Institute of Information and Communications Technology

Yu Kataoka

Shingo Takano

Norikazu Miyazaki

Kosuke Okahashi

Shotaro Hirata

Masayuki Motoya

Hideki Ichimei

Junichiro Ichikawa

Yuji Yamane

Minoru Shinozaki

Yuki Kugimoto

Yuya Yamaguchi

Yumi Murata

Shoutarou Hirata

Kenta Oishi

Naokatsu Yamamoto

An optical waveguide element includes a substrate, an optical waveguide disposed inside the substrate or on the substrate, and an electrode provided along the optical waveguide, working on the optical waveguide to generate a phase change in a light wave propagating through the optical waveguide. The electrode is a traveling-wave electrode. In a modulation section where the light wave is controlled by the electrode, the electrode and the optical waveguide are configured so that the phase change generated in a first modulation section located within a predetermined distance range from a downstream side end portion along a propagation direction of a traveling wave of an electrical signal propagating through the electrode has a sign opposite to a sign of the phase change generated in a second modulation section located within a predetermined distance range from an input end of the electrical signal on an upstream side along the propagation direction.

Optical waveguide element, optical waveguide device, and optical transmission apparatus

Provided is an optical waveguide element including spot size conversion means with suppressed optical insertion loss without complicating a manufacturing process. An optical waveguide element includes an optical waveguide substrate () having a rib-type optical waveguide () formed of a material having an electro-optic effect, and spot size conversion means for changing a mode field diameter of a light wave propagating through the optical waveguide at a position where an input end or an output end of the rib-type optical waveguide () is formed, in which the spot size conversion means includes a first configuration layer () that is connected to the rib-type optical waveguide () and includes a tapered portion () in which a width of the optical waveguide expands, a second configuration layer () that is laminated on the first configuration layer () and has a width narrower than a width of the first configuration layer (), and a third configuration layer () that is disposed to cover the second configuration layer () excluding a part of the second configuration layer () close to the rib-type optical waveguide and has a width wider than the width of the second configuration layer ().

Optical waveguide element, optical modulation device using optical waveguide element, and optical transmission device using optical waveguide element

An optical waveguide element that suppresses insertion loss related to coupling to an optical fiber or the like while miniaturizing the optical waveguide element is provided. There is provided an optical waveguide element including: a rib optical waveguide () that is made of a material () having an electro-optic effect; and the reinforcing substrate () that supports the optical waveguide, in which one end of the optical waveguide forms a tapered portion () of which a width narrows toward an end surface of the reinforcing substrate, a structure () made of a material having a higher refractive index than a material constituting the reinforcing substrate is provided so as to cover the tapered portion, and a coating layer () made of a material having a lower refractive index than the material constituting the structure is disposed so as to cover the structure.

Optical waveguide element, and optical modulation device and optical transmission apparatus using same

An optical waveguide element includes: a substrate on which an optical waveguide is formed; and an electrode that is formed on the substrate and controls a light wave propagating through the optical waveguide. The optical waveguide includes a protruding portion extending on the substrate, and the electrode includes a base layer made of Nb, and an upper layer formed on the base layer, the base layer being formed between the substrate and the upper layer. The occurrence of loss in propagating light is effectively suppressed due to the existence of the electrode that controls the propagating light in the optical waveguide element using the protruding optical waveguide.

Optical waveguide element and optical modulator

An optical modulator with which electrical connection between a signal electrode and signal wiring of a wiring substrate can be reliably made even in a case where a width of the signal electrode in an action portion of an optical control substrate is narrow is provided. An optical modulator includes an optical control substrate () that includes an optical waveguide (OW) including at least a branched waveguide which branches one light wave into two light waves, and that includes a control electrode for applying an electrical field to the branched waveguide, and a wiring substrate provided with a wiring which relays an electrical signal to be applied to the control electrode or with a wiring which terminates the electrical signal, in which the control electrode is provided with a signal electrode(S), the wiring is provided with signal wiring, and in a part (Sc) in which electrical connection is made between the signal electrode(S) and the signal wiring, a clearance (W) in which the branched waveguide (OW) sandwiches the signal electrode is wider than a clearance (W) in which the branched waveguide sandwiches the signal electrode in an action portion in which the control electrode applies the electrical field to the branched waveguide.

Optical modulator and optical transmission device using same

There is provided an optical waveguide device including a substrate, an optical waveguide formed on the substrate, and a working electrode that controls a light wave propagating through the optical waveguide, in which the working electrode includes a first base layer made of a first material, and a first conductive layer on the first base layer, and a conductor pattern including a second base layer made of a second material different from the first material and a second conductive layer on the second base layer is formed in a region other than a path from an input end to an output end of the optical waveguide, in a region on the substrate.

Optical waveguide device, optical modulator, optical modulation module, and optical transmission apparatus

An optical waveguide device includes a substrate, an optical waveguide formed on the substrate, two electrodes disposed at positions sandwiching the optical waveguide from both sides in a plane of the substrate; and a dielectric layer covering a top of the optical waveguide, wherein the dielectric layer extends in a width direction of the optical waveguide to an extent including edges of the two electrodes, facing the optical waveguide, and is disposed to partially cover each of the two electrodes.

Provided is an optical control element that can minimize an optical path difference between branched waveguides while reducing a difference in structure between the branched waveguides by disposing an input portion and an output portion of an optical waveguide on the same side of a substrate on which the optical waveguide is formed. An optical control element includes a substratehaving an electro-optic effect, an optical waveguideformed on the substrate, and a control electrode controlling a light wave propagating through the optical waveguide, in which an input portion (input light L) and an output portion (output light L) of the optical waveguide are formed on the same side of the substrate, the optical waveguide includes at least one Mach-Zehnder type optical waveguide portion (MZ) that has two branched waveguides () branched from one optical waveguide and combines the two branched waveguides to form one optical waveguide, and the branched waveguides have an even number of turned-back potions (A, A).

Optical control element, optical modulation device using same, and optical transmission apparatus

In order to provide an optical waveguide element that is capable of reducing coupling loss at a coupling portion with an optical fiber and of reducing propagation loss in an optical waveguide, the optical waveguide element comprises a supporting substrate and a waveguide layer consisting of a material having an electro-optic effect stacked on the supporting substrate, wherein a rib portion for forming an optical waveguide is provided protruding on an upper surface of the waveguide layer; a groove portion is formed on an upper surface of the supporting substrate directly below a part of the rib portion; and the groove portion is filled with a material having an effective refractive index comparable to that of the waveguide layer.

Optical waveguide element

Provided is an optical waveguide element that prevents leaked light generated at a forking section from entering a downstream optical waveguide such as another forking section, thereby affording minimal degradation of optical characteristics. The optical waveguide is characterized in that: at least one of two fork waveguides () forking from a first forking section () comprises a second forking section (); slab waveguides (-to-) are formed between the two fork waveguides; and between the first forking section and the second forking section, slits () are formed that partition the slab waveguides into a first slab waveguide area (-) close to the first forking section and second slab waveguide areas (--) close to the second forking section(s).

There is provided an optical waveguide device including: a substrate; an optical waveguide formed on the substrate; and a working electrode that controls a light wave propagating through the optical waveguide, in which the working electrode includes a first base layer made of a first material, a first conductive layer on the first base layer, a second base layer made of a second material different from the first material, which is on the first conductive layer, and a second conductive layer on the second base layer, and an edge of the second base layer is covered with the second conductive layer, in a cross-section perpendicular to an extending direction of the optical waveguide.

Optical waveguide device, manufacturing method of optical modulation element, optical modulator, optical modulation module, and optical transmission apparatus

An optical waveguide element includes a substrate and an optical waveguide that is disposed on the substrate. The optical waveguide has an effective refractive index change portion in which an effective refractive index of the optical waveguide related to a fundamental mode A parallel to a plane of polarization of a light wave propagated through the optical waveguide changes according to propagation of the light wave. In the effective refractive index change portion, a cross-sectional shape of the optical waveguide which is perpendicular to a propagation direction of the light wave is set such that the effective refractive index of the optical waveguide related to the fundamental mode A is higher than an effective refractive index of the optical waveguide related to another fundamental mode B perpendicular to the fundamental mode A.

Optical waveguide element, and optical modulation device and optical transmission apparatus using optical waveguide element

An optical waveguide device including a rib-type optical waveguideformed of a material having an electro-optic effect, and a reinforcing substratethat supports the rib-type optical waveguide, one end of the rib-type optical waveguidehas a tapered portion, structuresare provided that are disposed apart from the tapered portion so as to sandwich the tapered portion and are disposed on the reinforcing substrate, an upper substrate is disposed above the tapered portion and the structures, and an adhesive layer is disposed in a space sandwiched between the upper substrate and the structures.

Optical waveguide device

An optical waveguide element includes an optical waveguide which is formed on one surface of a substrate, an incidence part for light to be incident on the optical waveguide or an emission part for emitting light from the optical waveguide which is disposed in an end portion of the substrate, and a dielectric film which is formed on the optical waveguide of at least one of the incidence part and the emission part, and the vicinity thereof. Regarding the dielectric film, dielectric films including a dielectric film formed of a first material having an index of refraction higher than an index of refraction of the substrate and a dielectric film formed of a second material having an index of refraction lower than the index of refraction of the substrate are alternately laminated.

Optical waveguide element and manufacturing method therefor

In the optical waveguide device including an unnecessary-light waveguide for guiding unnecessary light emitted from a main waveguide, an emission waveguide connected to the unnecessary-light waveguide to emit the unnecessary light propagating through the unnecessary-light waveguide to the outside of the substrate is formed; an effective refractive index of the emission waveguide is set to be higher than an effective refractive index of the unnecessary-light waveguide; in a connection portion between the unnecessary-light waveguide and the emission waveguide, a centerline of the emission waveguide is inclined in a direction away from the main waveguide with respect to a centerline of the unnecessary-light waveguide; furthermore, in the connection portion, a position of the centerline of the emission waveguide is disposed to be shifted to a position further away from the main waveguide with respect to a position of the centerline of the unnecessary-light waveguide.

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Tokyo, Japan

Yu Kataoka