Sumitomo Electric Industries, Limited

Sumitomo Electric Optifrontier Co., Ltd.

Hitoshi Hatayama

Masayuki Nishimura

Eisuke Sasaoka

Chisai Hirose

Akira Inoue

Masayuki Shigematsu

Tetsufumi Tsuzaki

Motoki Kakui

Takatoshi Kato

Hiroshi Suganuma

Makoto Katayama

Takemi Hasegawa

Tomohiko Ueda

Nobuhiro Akasaka

Hiroshi Kohda

Koji Nakazato

Kenichiro Otsuka

Kazuya Masuda

Eiichiro Yamada

Kunio Awazu

Tsuneari Ito

Yoshifumi Hishikawa

Tatsuhiko Shitomi

Toshihiro Kushibiki

A measurement system includes a measurement device including a light source, and a first power meter, and one or a plurality of connection members each configured to optically connect a pair of optical fiber lines of the plurality of optical fiber lines. A first optical fiber line of the pair of optical fiber lines includes a first end and a second end, a second optical fiber line of the pair of optical fiber lines includes a third end and a fourth end, the one or plurality of connection members optically connect the second end to the fourth end, the light source causes testing light to be incident on the first end, and the first power meter measures first intensity of first output light output from the third end by causing the testing light to propagate through the pair of optical fiber lines.

Measurement system

A laser processing apparatusincludes a processing light sourceemitting processing light; an observation light emitting unitemitting observation light; optical fibersconducting light having a plurality of wavelengths generated at an electronic component; a detecting unitdetecting the light conducted by the optical fibers; and a control unitcontrolling a light emitting state of the processing light emitting unit. The optical fibersare categorized into four groups, and disposed so as to surround an optical fiberconducting the processing light. The optical fiberscategorized into the four groups are capable of conducting the observation light to the electronic componentevery group.

Laser processing apparatus and processing method employed therein

The invention offers a technique that selectively differentiation-induces mesenchymal stem cells, which can differentiate to cells that constitute various tissues and organs, to osteoblasts. In addition, the invention offers a technique that differentiation-induces mesenchymal stem cells to osteoblasts with a simple operation that needs only short time and that is noninvasive. The inventors have found that the switch for the differentiation induction to osteoblasts is turned on by translocating biological clock-relevant factors existing in mesenchymal stem cells from the cells' cytoplasm to the cells' nucleus. The inventors have also found that the switch can be turned on by irradiating the cells for a short time with a lightwave having a specific wavelength that is noninvasive.

Method of differentiation induction to osteoblasts

An optical multi/demultiplexer having a desirable multiplexing-and-demultiplexing performance throughout the entire wavelength band for signal transmission, and an optical multiplexer whose multiplexing performance is less susceptible to the shift of the center wavelength and to the fluctuation of the center wavelength due to temperature change and whose optical circuit can be miniaturized. The optical multi/demultiplexer comprises a substrate and an optical circuit formed on the substrate. The optical circuit comprises a circuit having a wavelength dependency, which may be a Mach-Zehnder interferometer (MZI), and a Y-junction. In one aspect of the optical circuit, the Y-junction is connected to one end of each of the two optical waveguides included in an MZI. In another aspect of the optical circuit, the Y-junction is connected to one end of an optical waveguide included in an MZI and to one end of another optical waveguide, whether it is independent or belongs to another MZI.

Optical multi/demultiplexer

The present invention relates to an optical component and others in structure capable of implementing improved compensation for a gain slope. The optical component is equipped with first and second Mach-Zehnder interferometers. The first Mach-Zehnder interferometer is provided with a first temperature controller for controlling a temperature of at least one of a part of an optical main path and a first optical side path, while the second Mach-Zehnder interferometeris also provided with a second temperature controller for controlling a temperature of at least one of a part of the optical main path and a second optical side path. A filter circuit having a wavelength-dependent insertion loss is disposed between the first and second Mach-Zehnder interferometers, and a controller controls the temperatures of the optical paths by use of the first and second temperature controllers on the basis of the insertion loss of the filter circuit, thereby setting a loss for light of a predetermined wavelength propagating between a light input end and a light output end.

Optical component, optical amplification module, and optical transmission system

A optical filter has a loss spectrum whose gradient dL/d&#x3bb; of a loss L (dB) with respect to the wavelength &#x3bb; (nm) is variable in the wavelength band of multiplexed signal light. A control circuit detects each power of signal light components demultiplexed by an optical coupler and controls the power of optical pumping light to be supplied to an optical amplification section from an optical pumping light sources such that the power of output signal light has a predetermined target value. The control circuit also controls the gradient dL/d&#x3bb; of the optical filter on the basis of powers of the signal light components.

Optical amplifier and optical amplification method

Provided herein are a planar optical circuit and optical transmission system in which signal light power can be adjusted with respect to signal light and light that is different from the wavelength band of the signal light can be maintained satisfactorily. The planar optical circuit is composed of a filter that can cause loss of variable wavelength dependence to signal light of a signal light wavelength band such that signal light input from a signal light input end is caused to have loss at given wavelength dependent loss by filter and is output from signal light output end

Planar optical circuit and optical transmission system

The invention provides a planar lightwave circuit type variable optical attenuator in which a small PDL is maintained even when an attenuation is large. The variable optical attenuator is constituted by a Mach-Zehnder interferometer comprising a substrate, two optical waveguide arms buried in a clad formed on the substrate, and thin-film heaters disposed on the surface of the clad and adjusting optical lengths of the optical waveguide arms. The optical waveguide arms are each made of a silica-based glass material, and a difference &Dgr;L between arm lengths is set to be in the range of 0.38 &mgr;m to 0.52 &mgr;m.

Planar lightwave circuit type variable optical attenuator

The invention provides an apparatus for and method of monitoring wavelength multiplexed signal light, which can obtain monitored data for multi-channel optical signals contained in the wavelength multiplexed signal light, which can avoid a large size and complicated structure and high cost of monitoring apparatus, and which can easily monitor the wavelength multiplexed signal light. The invention also provides an optical transmission system employing the monitoring apparatus and method. An optical filter being able to control a loss pattern is disposed on a monitoring waveguide for the wavelength multiplexed signal light, which is branched for monitoring from an input waveguide and an output waveguide constituting a main optical transmission path in a wavelength multiplexed signal light monitoring apparatus. While the optical filter sets a plurality of loss patterns in sequence, the wavelength multiplexed signal light having passed through the optical filter is detected by a photodiode for each of the loss patterns, and monitored data of the wavelength multiplexed signal light can be obtained from detected data.

Apparatus for and method of monitoring wavelength multiplexed signal light as well as optical transmission system using the same

Wavelength division multiplexing signal light is fed into an arrayed diffraction grating type optical demultiplexer, demultiplexed signal light components are outputted from a plurality of output ports, whether there is a signal light component or not is detected by each photodiode of a photodiode array, and a counter unit calculates the number of signals from the result of detection. Here, the output wavelength interval of &Dgr;&lgr;o of the output ports is set to &Dgr;&lgr;o&equals;&Dgr;&lgr;i/m (where m is an integer of at least two) with respect to the signal wavelength interval &Dgr;&lgr;i of the wavelength division multiplexing signal light, whereas the photodiode array is sectioned into m photodiode array groups in which the output signal wavelength interval is &Dgr;&lgr;i.

Wavelength division multiplexing signal number monitoring apparatus and method

A main optical path and an auxiliary optical path which are formed in a substrate are optically coupled to each other with a plurality of optical couplers, so as to constitute a Mach-Zehnder interferometer. By controlling the temperature regulation of main and auxiliary optical paths effected by heaters, a control unit regulates the transmissivity of light across an optical input end and an optical output end. Respective optical path lengths of the main and auxiliary optical paths are set so as to lower birefringence when optical loss becomes greater.

Optical device and control method thereof

A main optical path disposed between light input and output ends and an auxiliary optical path disposed so as to correspond to the main optical path are optically coupled to each other with first, second, and third optical couplers. The respective optical path lengths of main and auxiliary optical paths differ from each other between the first and second optical couplers and between the second and third optical couplers. Between the first and second optical couplers and between the second and third optical couplers, at least one of the main and auxiliary optical paths is provided with temperature adjusting means for adjusting the temperature of the corresponding optical path.

Optical filter

Three Mach-Zehnder interferometers to are connected in a series between an optical input terminal and an optical output terminal in an optical filter. Each interferometer is composed of two optical paths optical coupled at both ends by optical couplers. Only one interferometer has same optical path lengths between optical couplers. Heaters are disposed on each optical paths to allow the slope of transmission loss to change through the adjustment of the phase shift between those respective optical paths.

A planar lightwave circuit (PLC) of a PLC module is provided with many waveguides including a plurality of input (output) optical waveguide on a substrate. Junction faces between these input (output) optical waveguide and input (output) optical fibers are slant against the optical axis thereof. The PLC module has photodetectors opposed to corresponding junction faces disposed at the input-optical-fiber's-side (output-optical-waveguide's-side).

Planar lightwave circuit module

The present invention relates to an optical filter comprising a simple structure which easily realizes slope control of loss spectrum in a signal wavelength band as a gain equalizer. The optical filter comprises a first Mach-Zehnder interferometer constituted by a first part of a main optical line, a first auxiliary optical line, and first and second optical couplers which optically couple the main optical line and first auxiliary optical line to each other. The optical filter further comprises a second Mach-Zehnder interferometer constituted by a second part of the main optical line, a second auxiliary optical line, and third and fourth optical couplers which optically couple the main optical line and second auxiliary optical line to each other. In particular, in order for the slope of loss spectrum in a signal wavelength band to be adjustable while being centered about the amount of loss of light at a reference wavelength propagating through the main optical line from its entrance end to exit end, at least one of the first part of main optical line and the first auxiliary optical line is provided with a first temperature regulating device, at least one of the second part of main optical line and the second auxiliary optical line is provided with a second temperature regulating device, and the first and second temperature regulating devices are controlled by a control system.

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Yokohama, Japan

Hitoshi Hatayama