Fujitsu Corporation

Fujitsu Optical Components Limited

Tdk Corporation

Masaharu Doi

Yoshinobu Kubota

Yasuhiro Ohmori

Tadao Nakazawa

Takehito Tanaka

Masaki Sugiyama

Tetsuo Ishizaka

Shintaro Takeuchi

Shinji Maruyama

Yoshihiko Yoshida

Akira Ishii

Tetsu Hasegawa

Shinji Taniguchi

Minoru Seino

Shuntaro Makino

Teruo Kurahashi

Masaaki Ohyama

Takashi Shiraishi

Shinji Iwatsuka

Kazuhiro Tanaka

Hiroki Hara

Shuuichi Miyawaki

Takashi Kikukawa

Hideyuki Miyata

Toshinori Matsuura

Kenji Endou

Takashi Yamane

Masaaki Norimatsu

Teruhiro Kubo

Tetsuya Miyatake

Yumi Nakazawa, Legal Representative

Yoshihiko Kaitoh

Kunio Sugeta

Kenji Sasaki

Yasuhiro Omori

Yoshihiro Takahashi

Masami Kamioka

Yuki Sakurai

Tomoyuki Itou

Naoyuki Mekada

Yoshitada Kawashima

Tadao Nakazawa, Deceased

Osamu Oyama

An optical device includes an X-cut substrate, and a first waveguide and a second waveguide each being formed on the substrate and having a folding structure. The optical device includes a first signal electrode to generate a first electric field, and a second signal electrode to generate a second electric field with a reverse phase as compared to the first field. The first waveguide includes a first waveguide on an outward side to which the first field is applied from the first signal electrode, and a first waveguide on a return side to which the second field is applied from the second signal electrode. The second waveguide includes a second waveguide on the outward side to which the first field is applied from the first signal electrode, and a second waveguide on the return side to which the second field is applied from the second signal electrode.

Optical device and optical communication apparatus

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.

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 optical waveguide device includes an intermediate layer, a thin-film LN layer including X-cut lithium niobate, and a buffer layer stacked on a substrate; an optical waveguide formed in the thin-film LN layer; and an electrode for driving. The intermediate layer is formed by an upper first intermediate layer and a lower second intermediate layer, the second intermediate layer having a permittivity that is smaller than a permittivity of the first intermediate layer.

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.

An optical module includes a driver that is provided on a board and generates an electrical signal according to a data signal, and an optical modulator that is connected to an optical fiber and provided on the board and that modulates light emitted from the optical fiber using the electrical signal generated by the driver. The optical module has a cut-out portion that is formed by cutting out part of its outer shape and that accommodates the driver so that the driver overlaps the optical fiber when viewed from a direction perpendicular to the board.

Optical module and optical modulator

An optical modulator connected to a first optical fiber and a second optical fiber arranged in parallel includes an optical-path changing unit that redirects light emerging from a tip of the first optical fiber toward a tip of the second optical fiber and an optical modulation chip that modulates the light redirected by the optical-path changing unit and outputs a light beam obtained by modulating the light to a tip of the second optical fiber.

Optical modulator and optical module

An optical module includes a driver that generates an electric signal and an optical modulator that has a notch in which at least a portion of the driver is accommodated and performs optical modulation using an electric signal generated by the driver. The optical module also includes a first connector electrically connected to the driver in the notch of the optical modulator. The optical module further includes a second connector provided on a surface of the notch of the optical modulator, the surface being opposed to the first connector. The second connector is electrically connected to the optical modulator. Furthermore, the optical module includes a coaxial pin that is connected to the first connector and the second connector and transmits the electric signal generated by the driver to the optical modulator.

Optical module

An optical modulator includes an optical modulator chip configured to optically modulate an optical signal using an electrical signal input thereto; and a relay substrate configured to relay and couple the electrical signal to the optical modulator chip. The optical modulator chip includes a signal electrode and a ground electrode for the electrical signal, formed along a waveguide for the optical signal. One end of the optical modulator chip is arranged to face the relay substrate. An electrode connection portion coupling the electrical signal to the relay substrate by wire is provided at the one end. A distance between a tip of one end of the signal electrode in the electrode connection portion and the end of the optical modulator chip is less than a distance between a tip of an end of the ground electrode in the electrode connection portion and the end of the optical modulator chip.

Growing community of inventors

Kawasaki, Japan

Masaharu Doi