Fujitsu Optical Components Limited

Tdk Corporation

Shintaro Takeuchi

Masaharu Doi

Yoshinobu Kubota

Yasuhiro Ohmori

Takehito Tanaka

Shinji Maruyama

Hiroshi Kato

Kohei Shibata

Shinji Iwatsuka

Hiroki Hara

Yoshihiko Yoshida

Teruhiro Kubo

Seimi Sasaki

Takashi Kikukawa

Toshinori Matsuura

Shuntaro Makino

Kenji Endou

Teruo Kurahashi

Masaki Sugiyama

Kenji Sasaki

An optical device includes a thin film Lithium Niobate (LN) layer, a first optical waveguide, and a second optical waveguide. The thin film LN layer is an X-cut or a Y-cut LN layer. The first optical waveguide is an optical waveguide that is formed on the thin film LN layer along a direction that is substantially perpendicular to a Z direction of a crystal axis of the thin film LN layer. The second optical waveguide is an optical waveguide that is routed and connected to the first optical waveguide. At least a part of a core of the first optical waveguide is made thicker than a core of the second optical waveguide.

Optical device and optical communication apparatus

An optical waveguide device includes a substrate on which an intermediate layer, a thin-film LN layer of lithium niobate, and a buffer layer are stacked; an optical waveguide formed in the thin-film LN layer; and a plurality of electrodes near the optical waveguide. The intermediate layer and the buffer layer contain a same material of a metal element of any one of group 3 of group 18 of a periodic table of elements.

Optical waveguide device

An optical waveguide device has a substrate, an intermediate layer, a thin-film LN layer containing an X-cut lithium niobate, and a buffer layer stacked on the substrate, and an optical waveguide having a ridge shape formed in the thin-film LN layer. The optical waveguide device includes a plurality of electrodes provided, respectively, at a first side and a second side of the optical waveguide. The electrodes are disposed so that respective bottom surfaces thereof are at positions lower than a position of a surface of the buffer layer.

Optical waveguide device and method of manufacturing optical waveguide device

An electro-optic device is provided with a substrate, an optical waveguide formed of a lithium niobate film with a ridge shape on the substrate, and an electrode that applies an electric field to the optical waveguide. The optical waveguide includes a first waveguide section provided at least in an electric field application region applied with the electric field and having a thickness of 1 &#x3bc;m or larger and a second waveguide section provided in a region other than the electric field application region and having a thickness of 0.3 &#x3bc;m or larger and less than 1 &#x3bc;m.

Electro-optic device

An electro-optic device is provided with a Mach-Zehnder optical waveguide including at least one linear section and at least one curved section and a differential RF signal electrode provided along the Mach-Zehnder optical waveguide. Optical input/output ports of the Mach-Zehnder optical waveguide are provided at one end side in a first direction in which the linear section extends. The differential RF signal electrode is provided in both the linear and curved sections.

An optical modulator is provided with a ridge-shaped optical waveguide formed of a dielectric thin film having electro-optic effect, a buffer layer covering the optical waveguide, a signal electrode formed on the buffer layer so as to be opposed to the optical waveguide through the buffer layer; a ground electrode formed on the buffer layer together with the signal electrode, and a dielectric film having a higher dielectric constant than air and covering at least a part of exposed surfaces of the signal electrode and ground electrode and exposed surfaces of the buffer layer.

Optical modulator

An optical modulator is provided with a substrate, first and second optical waveguides each formed of a ridge-shaped electro-optic material film and disposed so as to be mutually adjacent on the substrate, a buffer layer covering upper surfaces of the first and second optical waveguides, first and second signal electrodes provided above the buffer layer so as to be opposed respectively to the first and second optical waveguides, and a dielectric layer covering at least one of a part of an exposed surface of the first signal electrode and a part of an exposed surface of the second signal electrode, and a part of an upper surface of the buffer layer. Differential signals are applied to the first and second signal electrodes.

An optical modulator includes an optical waveguide of a ridge type formed of a thin film of a dielectric material having an electro-optic effect over a substrate, a buffer layer covering the optical waveguide, and a signal electrode provided over the optical waveguide via the buffer layer, wherein a width of the signal electrode is greater than a ridge width of the optical waveguide and wherein the signal electrode covers at least one of sidewalls of a ridge of the optical waveguide.

Optical modulator, optical modulator module, and optical transmitter module

An optical modulator includes a substrate and an optical waveguide group. The optical waveguide group includes a pair of relay optical waveguides, a pair of first Mach-Zehnder type optical waveguides, and a pair of second Mach-Zehnder type optical waveguides. The pair of the first Mach-Zehnder type optical waveguides are connected to the pair of the relay optical waveguides and includes input ends arranged at positions that deviate from each other in a longitudinal direction of the substrate. The pair of the second Mach-Zehnder type optical waveguides are provided on a pair of branched waveguides of each of the first Mach-Zehnder type optical waveguides and includes input ends arranged at symmetric positions with respect to a straight line that passes through an input end serving as a branch point of the branched waveguides and that extends in the longitudinal direction of the substrate.

A first lens transmits a beam of light having a vertical cross-sectional diameter made closer to a horizontal cross-sectional diameter. The beam of light is emitted from an optical waveguide on a substrate and configured such that the vertical cross-sectional diameter which is the diameter of a vertical cross section along the direction of the thickness of the substrate is greater than the horizontal cross-sectional diameter which is the diameter of a horizontal cross section along the direction of the width of the substrate. A second lens is disposed at a position, at which the vertical cross-sectional diameter and the horizontal cross-sectional diameter coincide with each other, so as to focus the beam of light on the optical fiber. The position is closer to the optical fiber than the first lens along the direction of travel of the beam of light transmitted by the first lens.

Optical transmitter

A polarization combiner includes: a base member that includes a body portion, an arm portion extending from the body portion, and a notch portion surrounded with the body portion and the arm portion; a polarization rotating element that is fixed to the arm portion of the base member and that rotates a polarization direction of a first polarized wave; and a polarization combining element that is fixed to the base member so as to face the notch portion of the base member and the polarization rotating element, the polarization combining element combining two polarized waves entering from a surface facing the notch portion and the polarization rotating element, the two polarized waves including the first polarized wave whose polarization direction is rotated by the polarization rotating element and a second polarized wave passing the notch portion.

Polarization combiner and optical modulation device

An optical receiver circuit includes a polarization beam splitter configured to split input signal light into two different polarized wave components; two variable optical attenuators configured to respectively adjust attenuation of and output the signal light split by the polarization beam splitter according to polarization state; and a single planar optical waveguide on which the polarization beam splitter and the two variable optical attenuators are disposed.

Optical receiver circuit

An optical module connected to an optical fiber for transmitting light includes: a substrate; a ferrule that is formed from a material capable of transmitting therethrough light having a predetermined wavelength, accommodates an end of the optical fiber, and is fixed on the substrate with a fixing agent cured by being irradiated with the light capable of passing through the material; and a semiconductor chip that is disposed on the substrate and modulates light emitted from the end of the optical fiber accommodated in the ferrule.

Optical module and optical modulation device

An optical transmitting apparatus includes: a substrate; optical modulators that are arranged in parallel to one another on the substrate and modulate light; waveguides that are formed on the substrate and guide signal light represented by at least one of modulated light beams obtained by the light being modulated by the plurality of optical modulators and monitor light represented by at least another one of the modulated light beams other than the signal light; lenses that collimate the signal light and the monitor light emitted from the waveguides; and a holding member that causes the signal light and the monitor light to be emitted from the lenses in mutually-different directions, by holding the lenses in such a manner that the optical axis of at least one of the lenses is out of alignment in a predetermined direction with the optical axis of at least one of the waveguides.

Growing community of inventors

Sapporo, Japan

Shintaro Takeuchi