Fujitsu Optical Components Limited

Fujitsu Corporation

Masaki Sugiyama

Masaharu Doi

Tadao Nakazawa

Akira Ishii

Yoshinobu Kubota

Takehito Tanaka

Shinji Maruyama

Yoshihiko Yoshida

Masaaki Ohyama

Shinji Taniguchi

Norihisa Naganuma

Yasuhiro Ohmori

Shuntaro Makino

Seimi Sasaki

Yumi Nakazawa, Legal Representative

Eiichi Kodera

Kazumasa Takabayashi

Tamotsu Akashi

Kazuhiro Tanaka

Koji Otsubo

Shintaro Takeuchi

Teruo Kurahashi

Yoshitada Kawashima

Toyokazu Sasaki

An optical device includes an optical waveguide, a buffer layer that is layered on the optical waveguide, and an electrode that is arranged on a surface of the buffer layer that is layered in a part near the optical waveguide and that applies an electric signal to the optical waveguide. The optical device further includes a slit that is formed in the buffer layer, that extends from the surface of the buffer layer to a vicinity of the optical waveguide, and that is filled with part of the electrode.

Optical device and optical communication device

An optical device includes a rib waveguide that is a thin-film lithium niobate (LN) crystal, a buffer layer that is laminated on the rib waveguide, and an electrode that applies voltage to the rib waveguide. The buffer layer includes a thick-film part that is laminated on a rib of the rib waveguide, and thin-film parts that are laminated on slabs of the rib waveguide, where the slabs are located on both sides of the rib, and that have smaller thicknesses than a thickness of the thick-film part.

Optical modulator and optical communication apparatus

An optical device includes a substrate W, a RF modulating unit, and a phase adjustment unit. The RF modulating unit is provided on the substrate W and modulates light in accordance with a RF signal. The phase adjustment unitis provided on the substrate W and adjusts the phase of an optical signal modulated by the RF modulating unit. The phase adjustment unitincludes a heaterand a to-be-heated optical waveguide. The to-be-heated optical waveguideis provided between a thin film LN substrateand a buffer layerof the substrate W, and is formed of a material having a thermo-optical effect. The heateris provided at a position opposite the to-be-heated optical waveguide, with the buffer layertherebetween on the substrate W, and heats the to-be-heated optical waveguide

Optical device and optical transceiver

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 device includes an optical modulator formed on a substrate. The optical device includes: a signal electrode for the optical modulator that is formed on the substrate; a ground electrode for the optical modulator that is formed on the substrate; an optical waveguide that is provided in a region between the signal electrode and the ground electrode; a first buffer region that is formed between the optical waveguide and the substrate; and second buffer regions that are formed between the optical waveguide and the signal electrode and between the optical waveguide and the ground electrode. A permittivity of the second buffer regions is higher than a permittivity of the first buffer region.

Optical device that includes optical modulator, and optical transceiver

An optical device includes an optical coupler that inputs an optical signal received from a light source, a semiconductor optical amplifier that amplifies the optical signal received from the optical coupler, and a light receiving element that receives spontaneous emission light received from the semiconductor optical amplifier. The optical coupler includes a first input port to which the optical signal received from the light source is input, a second input port that is connected to an input stage of the light receiving element and that is different from the first input, and an output port that is connected to an input stage of the semiconductor optical amplifier, and that outputs optical signal received from the first input port to the semiconductor optical amplifier. The light receiving element receives, via the output port and the second input port, spontaneous emission light received from the semiconductor optical amplifier.

Optical device, optical transmission apparatus, optical reception apparatus, and optical communication apparatus

An optical device includes an optical waveguide that is a rib type and that is formed of a thin film lithium niobate (LiNbO: LN) substrate using a thin film LN crystal, and a buffer layer that is laminated on the optical waveguide. Furthermore, the optical device includes an electrode that is laminated on the buffer layer and that applies a voltage to the optical waveguide, and a gettering site that is disposed parallel to the optical waveguide and that traps an electric charge inside the optical waveguide.

An optical device includes an optical waveguide formed of a crystal thin film having an electro-optic effect, an RF electrode configured to apply a high-frequency voltage to the optical waveguide, and a DC electrode configured to apply a DC voltage to the optical waveguide, wherein the RF electrode has a coplanar electrode configuration, and the DC electrode has a microstrip electrode configuration.

Optical device and optical transceiver using the same

An optical device includes a plurality of first Si waveguides that split and output an optical signal received from an input unit, plurality of LN waveguides that are included in a LN modulator and that transmit the optical signals that are split and output by the first Si waveguides, and a plurality of second Si waveguides that multiplex and output the associated optical signals that are output from the plurality of respective LN waveguides. The device includes an output unit that outputs the optical signal multiplexed by the second Si waveguides, and a plurality of Mach-Zehnder interferometers disposed on each of waveguides connected by the first Si waveguides, the LN waveguides, and the second Si waveguides, respectively. When there are differences among waveguide lengths of the LN waveguides, the device is configured such that the optical path lengths of the waveguides for the respective Mach-Zehnder interferometers are equalized.

An optical device includes an optical waveguide, a buffer layer that is layered on the optical waveguide, and an opening that is formed at least in the buffer layer above a part near a side surface of the optical waveguide. The optical device further includes an electrode that is layered in the opening and that is configured to apply a signal to the optical waveguide and a silicon layer that is layered on the buffer layer excluding the opening.

An optical device includes a substrate, a layered structure provided on the substrate and including an intermediate layer, an optical waveguide formed of a thin crystal film having an electro-optic effect, and a buffer layer stacked in this order, and an electrode provided on or above the buffer layer and configured to apply a direct current voltage to the optical waveguide. The resistivity of the intermediate layer is higher than the resistivity of the buffer layer.

An optical device includes a modulator and a tap coupler. The modulator includes an optical waveguide that is formed of a thin-film lithium niobate (LN) substrate and through which light passes, and an electrode that applies voltage to the optical waveguide, and modulates a phase of light that passes through the optical waveguide in accordance with an electric field in the optical waveguide, where the electric field corresponds to the voltage. The tap coupler includes at least a part formed of the thin-film LN substrate, and splits a part of the light that passes through an inside of the optical waveguide. The tap coupler includes a delayed interferometer that splits a part of the light that passes through the optical waveguide, at a split ratio corresponding to a phase difference of light that passes through an inside of the tap coupler from the optical waveguide.

An optical device includes: a ground electrode having a ground potential; a thin film optical waveguide formed by a thin film substrate stacked on the ground electrode; a signal electrode that is arranged at a position facing the ground electrode across the thin film optical waveguide and that transmits a high frequency signal; and a dielectric that covers at least a part of an exposed surface of the signal electrode.

An optical device includes an optical circuit and a test circuit optically connected to the optical circuit. The test circuit includes a first grating coupler configured to receive test light, a second grating coupler configured to output, as reference light, the test light passed through the first grating coupler, and a first branch coupler connected to an output of the first grating coupler. The first branch coupler includes first output connected to an input of the optical circuit and configured to branch and output the test light from the first grating coupler to the optical circuit. Further, the first branch coupler includes a second output connected to an input of the second grating coupler and configured to branch and output the test light from the first grating coupler to the second grating coupler.

Optical device for measuring power of test light and optical device testing method

An optical device with an optical transmitter circuit and an optical receiver circuit integrated on a substrate has at least one of a first oblique waveguide extending obliquely with respect to an edge of the substrate at or near an incident port for introducing a light emitted from a light source to the optical device, a second oblique waveguide extending obliquely with respect to the edge of the substrate at or near a signal receiving port optically connected to the optical receiver circuit, and a third oblique waveguide extending obliquely with respect to the edge of the substrate at or near a signal transmission port optically connected to the optical transmitter circuit.

Growing community of inventors

Kawasaki, Japan

Masaki Sugiyama