Shigenori Aoki

6819818, Nov 16, 2004

Dec 26, 2002

10/330446

Shigenori Aoki - Sunnyvale CA

Fujitsu Limited - Kawasaki

G02B 635

385 16, 385 17, 385 18

An optical switch having a common waveguide and optical properties to improve switch performance is presented. The common waveguide is located between a first plural light deflection elements and a second plural light deflection elements, each including prisms made by electro-optic material. The common waveguide material is selected to improve switch performance by increasing the deflection of the light deflecting elements and/or reducing the effects induced by birefringence from the electro-optical material. The present invention can be used in optical switch designs having common waveguides or other optical switches.

6917748, Jul 12, 2005

Jul 1, 2003

10/611704

Alexei Glebov - San Mateo CA, US
Shigenori Aoki - Sunnyvale CA, US

Fujitsu Limited - Kawasaki

G02B006/00

385140, 385 2, 385 14, 385131

The intensity of signals in optical networks can be controlled using a variable optical attenuator (VOA). The present invention is a VOA that is particularly well suited for optical networks, for example to provide channel-by-channel normalization of gain control of wavelength division multiplexed signals. The inventive VOA includes a waveguide having an electro-optical material and electrodes that produce an electric field within the electro-optical material when a voltage difference is applied to the electrodes. The electro-optical material can either be a substrate or can be a layer deposited on a substrate. In an alternative embodiment, a polarization independent VOA is formed from a waveguide that includes two, end-to-end waveguides. In one embodiment, a 90 degree polarization rotator is provided between the two waveguides. In another embodiment, each of the two waveguides has a different electro-optical material selected to selectively pass one of two 90 degree polarizations.

7027670, Apr 11, 2006

Oct 17, 2003

10/688518

Shigenori Aoki - Sunnyvale CA, US

Fujitsu Limited - Kawasaki

G02F 1/295

385 10, 385 8, 385 16, 385 17, 385 20, 385 40

Cascaded optical deflectors are formed from light deflecting elements of an electro-optical material that are individually controlled according to applied voltage differences across the elements. The shape of the elements are determined by the shape of the electrodes on either side of the electro-optical material, while the refractive index is controlled by the sign and magnitude of a voltage difference applied across the elements. In particular, the invention includes light deflection elements that are tilted with respect to one another and that are individually controlled to provide for the deflection of light in an improved manner.

7035524, Apr 25, 2006

Dec 26, 2002

10/330785

Shigenori Aoki - Sunnyvale CA, US
Kishio Yokouchi - San Jose CA, US

Fujitsu Limited - Kawasaki

G02B 6/00

385140, 385 33, 385 36

A system and method is provided for attenuating a light signal. One embodiment includes a method for causing optical attenuation in a waveguide, where the waveguide has an input port for receiving a light signal and an output port for output of an attenuated light signal. First, an electric field is generated in at least a portion of the waveguide, such that a first refractive index in that portion of the waveguide is changed to a second refractive index. Next, the light signal in the waveguide is directed from the input port to the output port through the electric field. And lastly, the light signal is attenuated as a function of the electric field. The light signal may be attenuated, for example, by changing the deflection angle, changing the beam collimation width or from emitting part of the light signal from the waveguide before the light signal reaches the output port.

7043132, May 9, 2006

Jan 21, 2004

10/761619

Shigenori Aoki - Sunnyvale CA, US
Kishio Yokouchi - San Jose CA, US
Hiroshi Nagaeda - Kitahiroshima, JP
Kaoru Sugimoto - Kawasaki, JP
Alexei Glebov - San Mateo CA, US

Fujitsu Limited - Kawasaki

G02B 6/00

385140, 385 8, 385 40

The intensity of signals in optical networks can be controlled using a variable optical attenuator (VOA). The present invention is a VOA that is particularly well suited for optical networks, for example to provide channel-by-channel normalization of gain control of wavelength division multiplexed signals. The inventive VOA includes a waveguide having a cladding that includes an electro-optical material and electrodes that produce an electric field within the electro-optical material when a voltage difference is applied to the electrodes. The VOA also includes a layer that is parallel to the core of the waveguide and that optically couples to the core to receive light from the attenuated signal. A power meter receives light from the layer as an indication of the amount of light attenuated from the signal and for controlling the voltage to the electrodes.

7171083, Jan 30, 2007

Feb 4, 2004

10/771562

Kishio Yokouchi - San Jose CA, US
Lidu Huang - Danville CA, US
Shigenori Aoki - Sunnyvale CA, US

Fujitsu Limited - Kawasaki

G02B 6/35
G02F 1/295

385 41, 385 22, 385 9

An all-optical one-by-N optical switch is provided that has fewer components, is easier to control and has fewer optical losses that prior art one-by-N optical switches. An optical switch of the present invention includes an active deflection element formed from an electro-optical material to deflect an optical input from a single input to a selected one of N outputs. In one embodiment of the present invention, a single active deflection element at the input deflects an optical signal across a waveguide that commonly connects the N outputs. The N optical outputs include passive optical elements that are aligned with the deflected optical signal to accept a signal and provide it to a selected optical output. The optical switch can either be monolithic, where the optical material are all electro-optical materials, or can be hybrid, having separately formed components, such as the common waveguide, adhered to the substrate on which the optical switch is formed.

7224881, May 29, 2007

May 31, 2005

11/141880

Shigenori Aoki - Sunnyvale CA, US
Kishio Yokouchi - San Jose CA, US

Fujitsu Limited

G02B 6/00

385140, 385 40

An apparatus for attenuating a light signal is disclosed. The apparatus causes optical attenuation in a waveguide, where the waveguide has an input port for receiving a light signal and an output port for output of an attenuated light signal. First, an electric field is generated in at least a portion of the waveguide, such that a first refractive index in that portion of the waveguide is changed to a second refractive index. Next, the light signal in the waveguide is directed from the input port to the output port through the electric field. And lastly, the light signal is attenuated as a function of the electric field. The light signal may be attenuated, for example, by changing the deflection angle, changing the beam collimation width or from emitting part of the light signal from the waveguide before the light signal reaches the output port.

7283220, Oct 16, 2007

Mar 24, 2004

10/808665

Lidu Huang - Danville CA, US
Alexei Glebov - San Mateo CA, US
Shigenori Aoki - Sunnyvale CA, US
Michael G. Lee - San Jose CA, US
Kishio Yokouchi - San Jose CA, US

Fujitsu Limited - Kanagawa

G01N 21/41

356128

Methods and apparatuses for measuring the optical properties of solids, gels, and liquids are disclosed. The apparatuses may be constructed on miniature substrates using conventional semiconductor wafer and packaging processes. The substrates may be mass-produced on wafers, which are then diced to provide individual miniature substrates. High measurement precision, low-manufacturing costs, and other benefits are provided by the present inventions.