Fujitsu Corporation

Kazuhiro Tanaka

Goji Nakagawa

Hiroyuki Nobuhara

Masaharu Doi

Haruhiko Tabuchi

Koji Terada

Kazunori Miura

Kiyohide Wakao

Takashi Shiraishi

Satoshi Kuroyanagi

Hiroyuki Rokugawa

Seimi Sasaki

Nobuhiro Fujimoto

Youske Yamazaki

Masaki Sugiyama

Tsuyoshi Yamamoto

Yoshihiro Yoneda

Kazuyuki Mori

Yuji Tochio

Tamotsu Akashi

Naoki Yamamoto

Tetsu Hasegawa

Masaaki Norimatsu

Tetsuya Miyatake

Akira Fukushima

Taizo Nosaka

A polarization conversion device converts a polarization state of a light which is input to a first waveguide, that is, TE/TM mode of the light, to output it from the first waveguide. The polarization conversion device includes: a mode converter that performs the inter-conversion of TE/TM modes of the light which is input to the first waveguide; and a polarization separator that receives the light passed through the mode converter and separates the received light into a first light, TE/TM of which mode has been converted by the mode converter and a second light, TE/TM of which mode has not been converted, to output the first light to the first waveguide.

Polarization multiplexing modulator

Polarization conversion device and polarization multiplexing modulator

The application relates to an optical device for enhancing the stress to be generated in a substrate in comparison with a conventional technique. To this end, the optical device includes a substrate having a photoelastic effect, a first stress layer formed on a first face of the substrate and having a pattern for generating stress which induces refraction index variation by the photoelastic effect in a partial region in the substrate, and a second stress layer formed on a second face which is a reverse face to the first face of the substrate and configured to generate stress for restoring the shape from the deformation caused by the stress generated in the substrate by the first stress layer in the substrate.

Optical device having stress layer inducing refraction index variation in a partial region of a substrate by photoelastic effect

A waveguide type optical device includes a substrate where a waveguide is formed; a supplemental plate connected on the substrate by using an adhesive; and a groove forming part formed by cutting through the supplemental plate so as to reach the substrate and cut the waveguide, the groove forming part being where a functional thin film is inserted. The supplemental plate and the waveguide adhere to each other or come close to each other in a range not influencing a mode of light.

Waveguide type optical device and manufacturing method of the waveguide type optical device

Optical waveguides (A) and (B) of a Mach-Zehnder modulator is normally formed on a &#x2212;Z plane as an electric polarization non-inversion area. However, when the signal electrodeand the ground electrodeare provided asymmetrically on two waveguides, chirp occurs in output light, which is undesired. Therefore, these electrodes are provided symmetrically about the two waveguides. To effectively perform optical modulation, a part of the substrate in which an optical waveguide exists is to be electric polarization-inverted. As a result of the electric polarization inversion the optical waveguide is on the +Z plane. However, electric charge is accumulated on the +Z plane from unstable spontaneous electric polarization of an electric polarization inversion area, and has undesired influence on the performance of the optical modulator. Therefore, a conductive amorphous layer is formed on the surface of the electric polarization inversion area.

Optical device

In an optical modulator according to the present invention, a Mach-Zehnder optical waveguide is formed on a substrate having an electro-optic effect, a signal electrode and an earth electrode are disposed along a pair of branching waveguides of the optical waveguide, and an electric signal is applied on the signal electrode to thereby modulate a light being propagated through the optical waveguide. At this time, a first region and a second region are set in an interacting portion where the light and the electric signal interacts to each other, to form a polarization inversion region in each of the set regions, and also, an arrangement pattern of the signal electrode is determined so that a modulation direction in each of the set regions is opposite to each other. As a result, it is possible to realize the optical modulator of simple configuration capable of realizing simultaneously the broad modulation band and the wavelength chirping suppression.

Optical modulator

An optical module including a substrate having a groove; an optical waveguide layer formed on the substrate, the optical waveguide layer including an optical waveguide core having first and second ends, the first end being aligned with the groove, and an optical waveguide cladding covering the optical waveguide core; a ferrule having a through hole; and an optical fiber inserted and fixed in the through hole. The ferrule has a flat cut portion for semicylindrically exposing a part of the optical fiber inserted and fixed in the through hole. The ferrule is fixed at the flat cut portion to the substrate so that the part of the optical fiber exposed to the flat cut portion is inserted into the groove of the substrate until one end of the optical fiber abuts against the first end of the optical waveguide core.

Ferrule assembly and optical module

An insulation film (silicon dioxide film) is laminated on a platform substrate of Si, etc., and a transmitting unit wiring pattern and a receiving unit wiring pattern are provided on the insulation film. Although a base intruded in a convex shape is provided at the bottom of a light emitting device (LED) of the platform substrate, this base is not provided at the bottom of a light receiving device, and the insulation film under the light receiving device becomes thick. A groove is formed in a waveguide, and a WDM filter is mounted. A diamond or SiC layer can also be provided beneath the insulation film to improve the insulation resistance, and a conduction layer is provided beneath the diamond or SiC layer. Electrical crosstalk is suppressed by grounding the conduction layer. Optical crosstalk is improved by locating the LED at the entrance/exit of the WDM filter and the light receiving device on the opposite side.

Optical transmitting and receiving device and the manufacturing method

The invention is aimed at providing an optical switch using tilt mirrors, in which easy mounting of the optical components is possible by simplifying the construction, and in which a short spatial propagation distance for the light beam is realized. To this end, the optical switch using tilt mirrors of the present invention comprises; a collimator array and a tilt mirror array each formed with an input section and an output section aligned and integrated, and a shift type turn-back mirror that shifts the optical path of the incident light in a predetermined direction and turns back and outputs this. The construction is such that the light input to the input section of the collimator array is reflected by the input section of the tilt mirror array so that the optical path is changed, and is then sent to the shift type turn-back mirror, and the light which has been shifted and turned back by the shift type turn-back mirror is reflected by the output section of the tilt mirror array and output from the output section of the collimator array.

Optical switch using tilt mirrors

An optical module including a substrate, an optical waveguide formed on the substrate, and an optical element mounted on the substrate so as to be optically coupled to an end of the optical waveguide, for performing conversion between light and electricity. The optical module further includes a transparent resin for covering at least an optical coupling portion between the optical waveguide and the optical element, and a thermoplastic resin for covering only the optical element and its periphery including the transparent resin to seal the optical element.

Resin sealed optical module

A wavelength division multiplexing optical device includes a cladding layer formed on a waveguide substrate, a first optical waveguide embedded in the cladding layer, a second optical waveguide embedded in the cladding layer and connected at one end thereof to an intermediate portion of the first optical waveguide, and an insertion groove formed in the waveguide substrate and the cladding layer so as to extend across a connected portion of the first and second optical waveguides. The wavelength division multiplexing optical device further includes first and second wide grooves formed in the cladding layer so as to cover opposite end portions of the insertion groove and open to the opposite side surfaces of the cladding layer, and a wavelength selecting filter inserted in the insertion groove.

Growing community of inventors

Kawasaki, Japan

Kazuhiro Tanaka