Nippon Telegraph and Telephone Corporation

Nippon Telegraph and Telephone Public Corporation

Ntt Electronics Corporation

Norio Takato

Masao Kawachi

Kaname Jinguji

Yasuyuki Inoue

Katsunari Okamoto

Akio Sugita

Shin Sumida

Shigeru Oikawa

Takashi Kurokawa

Yuzo Katayama

Akira Miyashita

Nobuo Tomita

Yasuhiro Hida

Hisashi Izumita

Fumihiko Yamamoto

Fumiaki Hanawa

Yoshitaka Enomoto

Shinichi Furukawa

Mitsuho Yasu

Yuichi Kikuchi

Akira Morinaka

Hiroyuki Suda

Satoru Konno

Akihiro Takagi

Toshimi Kominato

Yasumori Ohmura

Jyunko Katoh

A Y branch circuit according to the present invention includes; a under clad; a circuit core, formed on the under clad and having a main core and two branch cores, connected to the main core, and an over clad that embeds the circuit core. The main core and the two branch cores are connected across an interval. The two branch cores have a width-to-height ratio of 50% to 150% and have a gap, at the main core end, that is narrower at the over clad side than at the under clad side.

Y branch circuit and method for manufacturing the same

An optical element module is equipped with a casing, an optical element provided inside the casing, a pipe which communicates the inside of the casing to the outside, and a primary coated optical fiber which is inserted through the pipe and connected to the optical element.

Optical element module with a primary coated optical fiber

An integrated optical waveguide circuit includes a substrate; an optical wavelength multiplexer and an optical power splitter formed on a same surface of the substrate. The optical wavelength multiplexer is composed of a first slab optical waveguide, a second slab optical waveguide, a single or a plurality of input optical waveguides connected to the first slab optical waveguide at one end of the first slab optical waveguide, a plurality of arrayed optical waveguides arranged in parallel and having different lengths and connected to the first slab optical waveguide and the second slab optical waveguide, and a plurality of output optical waveguides arranged in parallel and connected to the second slab optical waveguide. The optical power splitter is composed of the second slab optical waveguide, one or more input optical waveguides, and the plurality of output optical waveguides arranged in parallel and connected to the second slab optical waveguide.

Integrated optical waveguide circuit and optical branch line test system

A guided-wave optical branching component is composed of a Mach-Zehnder interferometer having two or more directional couplers. A slight difference .DELTA.L in the optical-path length is provided in two or more optical waveguides connecting the two or more directional couplers. The difference of the optical-path length is less than the shortest wavelength in the operational wavelength region of the guided-wave optical branching component, and the coupling ratio of each of the two directional couplers monotonically increases with wavelength in the operational wavelength region. By using the optical branching components thus constructed (i.e., Mach-Zehnder interferometer type 3-dB optical coupler) in conjunction with a phase shifter, a Mach-Zehnder interferometer type optical switch can be achieved.

Guided-wave optical branching components and optical switches

An integrated optical device includes a substrate; a single-mode optical waveguide having a cladding layer disposed on the substrate and a core portion embedded in the cladding layer for transmitting light therethrough; and a stress applying film disposed on a desired portion of the cladding layer for adjusting stress-induced birefringence of the single-mode optical waveguide by irreversibly changing the stress exerted on the core portion by a trimming technique. The integrated optical device can be manufactured by the steps of forming a cladding layer on a substrate; forming a single-mode optical waveguide having a core portion embedded in the cladding layer for transmitting light therethrough; and forming, on the cladding layer, a stress applying film for exerting a stress on the single-mode optical waveguide to irreversibly change the stress by trimming the film. The device exhibits a precisely adjusted birefringence and a desired polarization dependence or independence, and is effective for constructing an integrated optical device for optical communication, for optical sensing or for optical signal processing, in which the polarization characteristics play an important role.

Integrated optical device and method for manufacturing thereof

An integrated optical device includes a substrate; a single-mode optical waveguide having a cladding layer disposed on the substrate and a core portion embedded in the cladding layer for transmitting light therethrough; and a stress applying film disposed on a desired portion of the cladding layer for adjusting stress-induced birefringence of the single-mode optical waveguide by irreversibly changing the stress exerted on the core portion by a trimming technique. The integrated optical device can be manufactured by the steps of forming a cladding layer on a substrate; forming a single-mode optical waveguide having a core portion embedded in the cladding layer for transmitting light therethrough; and forming, on the cladding layer, a stress applying film for exerting a stress on the single-mode optical waveguide to irreversibly change the stress by trimming the film. The device exhibits a precisely adjusted birefringence and a desired polarization dependence or independence, and is effective for constructing an integrated optical device for optical communication, for optical sensing, or for optical signal processing, in which the polarization characteristics play an important role.

In a single mode optical waveguide having a substrate, a cladding layer formed on the substrate, a core portion embedded in the cladding layer, and an elongated member for applying a stress to the core portion or a stress relief groove for relieving a stress from the core portion in the cladding layer along the core portion. The position, shape and material of the elongated member or the groove are determined in such a way that stress-induced birefringence produced in the core portion in accordance with a difference in thermal expansion coefficient between the substrate and the single mode optical waveguide is a desired value.

Single mode channel optical waveguide with a stress-induced

Coordinate input apparatus

A polymer optical circuit with optical lead-fibers which comprise a plurality of optical fibers, each one end portion thereof being embedded in a transparent polymer film formed on a substrate, and polymer optical waveguides formed in the film between the embedded ends of the optical fibers so that the terminal ends of the optical waveguides are connected with the embedded ends of the optical fibers; the substrate, polymer film, polymer optical waveguide and optical fibers being formed as an integrated unit. A process for fabricating this polymer optical circuit is also disclosed.

Polymer optical circuit with optical lead-fibers and method of

Growing community of inventors

Katsuta, Japan

Norio Takato