Nec Corporation

Shinya Sudo

Kenji Sato

Koji Kudo

Kenji Mizutani

Noboru Yoshida

Makihiro Otohata

Kazuhiko Inoue

Mads L Nielsen

Jan De Merli

Daisuke Kawasaki

Takao Morimoto

Tomoaki Kato

Takashi Ohtsuka

Kazuhiro Shiba

Suguru Tamai

Koichi Naniwae

Jan De Merlier

Provided is an electrode for a battery which effectively suppress a short circuit between a positive electrode and a negative electrode at high temperature of the battery. The electrode includes a current collector, an active material layerformed on at least one side of the current collectorand an insulating layerformed on the surface of the active material layer. The electrode was formed so that peeling occurs between the current collectorand the active material layerand the peeling strength was 10 mN/mm or more when a 90° peeling test was performed at a peeling rate of 100/min.

Electrode for battery, battery having electrode and method for manufacturing electrode and battery having electrode

Disclosed is an electrode, comprising: a metal foil; an electrode layer formed on at least one surface of the metal foil; and an insulating layer formed on the electrode layer; wherein boundary portion between the insulating layer and the electrode layer is in a state in which a part of the insulating layer engages into a part of the electrode layer, and Ls/L is 1.25 or more, wherein a reference length of a straight line in a direction in which the metal foil extends is taken as L and a boundary length along boundary between the insulating layer and the electrode layer is taken as Ls.

Electrode and secondary battery

A negative electrode active material constituting a lithium ion secondary battery having high energy density and excellent cycle characteristics, and a negative electrode and a lithium ion secondary battery comprising the same are provided. The present invention relates to a negative electrode active material comprising graphite particles and crystalline silicon particles, wherein a median diameter of the crystalline silicon particles is 0.7 &#x3bc;m or less, and a weight ratio of the crystalline silicon particles to the total weight of the graphite particles and the crystalline silicon particles is 1 wt % or more and 25 wt % or less.

Negative electrode active material and lithium ion secondary battery using the same

A film package batteryhas a battery element () having a positive electrode, a negative electrode and a separator that are stacked or wound, wherein, at least at 200&#xb0; C., the separator does not melt or soften and has a heat shrinkage ratio of 3% or less; a film package () enclosing the battery element; and a fixing tape () fixed to a part of the battery element and fixed to an inner surface of the film package.

Film packaged battery

An optical A/D converter according to the present invention includes an optical splitter that splits an analog input signal light into plurals, a plurality of Mach-Zehnder interferometers to which each of the signal lights split by the optical splitter is input, and plurality of optical/electrical conversion unit that convert each signal lights output from each Mach-Zehnder interferometer into a digital electrical signal, in which each Mach-Zehnder interferometer includes optical intensity-to-phase conversion unit that optically convert intensity of the input signal light into an amount of phase shift and the amount of phase shift differs for each Mach-Zehnder interferometer. Then, it is possible to provide a high speed and low power consuming optical demodulation circuit.

Optical analog-to-digital converter, method of constructing the same, optical signal demodulator, and optical modulator-demodulator

An optical intensity-to-phase converter according to the present invention includes first and second waveguides to which a first input light is input, a third waveguide to which a second input light is input, and an interaction region that is provided in common on the second and third waveguides in which the first and second input lights are multiplexed and interact. The optical intensity-to-phase converter provides delay to output lights output from the first and second waveguides based on intensity of the first or second input light. Then, it is possible to provide an optical intensity-to-phase converter that enables simple configuration of an optical A/D converter.

Optical intensity-to-phase converter, mach-zehnder interferometer, optical A/D converter, and method of constructing optical intensity-to-phase converter

The present invention has an object to provide an optical modulation device and an optical modulation method that achieve an excellent spectral efficiency with a simple and compact configuration and low power consumption. An optical modulation device according to an exemplary aspect of the present invention includes a CW light source (), a coupler (), optical modulators () and (), an optical frequency shifter (), a serial-to-parallel converter (), and a delay circuit (). The serial-to-parallel converter () divides a data signal having a bit rate B into two data strings having a bit rate B/2, and extracts a clock signal (CLK). The delay circuit () temporally synchronizes the two data strings. CW light emitted from the CW light source is split into two beams by the coupler (). The optical modulators () and () generate optical signals by modulating the two split light beams according to the data strings. The optical frequency shifter () shifts center frequencies of the optical signals by &#x394;f=B/(2&#xd7;2) according to the clock signal (CLK).

Optical modulation device and optical modulation method

The invention provides a semiconductor optical modulator including a two-step mesa optical waveguide having a first clad layer (); a mesa-like core layer () formed over the first clad layer (); and a second clad layer () formed into a mesa shape over the core layer (), and having a mesa width smaller than that of the core layer (). The two-step mesa optical waveguide includes a multi-mode optical waveguide region to which an electric field is applied or into which an electric current is injected, and a single-mode optical waveguide region to which the electric field is not applied and into which the electric current is not injected. When the mesa width of the core layer in the multi-mode optical waveguide region is defined as W, and the mesa width of the core layer in the single-mode optical waveguide region is defined as W, W&#x3e;Wis satisfied.

Semiconductor optical modulator, semiconductor optical integrated device, and method of manufacturing the same

A semiconductor optical waveguide-A having an optical amplification function and a semiconductor optical waveguide-B having a light control function are integrated together on the same substrate. A facet of the semiconductor optical waveguide-A facing an isolation trench and a facet of the semiconductor optical waveguide-B facing the isolation trench are configured as a composite optical reflector/optical connector using an optical interference. The facet of the semiconductor optical waveguide-A achieves an optical reflectivity not higher than the reflectivity corresponding to a cleaved facet and not smaller than several percent, and an optical coupling coefficient of not lower than 50% between the semiconductor optical waveguide-A and the semiconductor optical waveguide-B.

Semiconductor laser, module and optical transmitter

The present invention provides an external resonator-type wavelength tunable laser device that can properly fulfill a wavelength tuning function even with the use of a planar wavelength tunable reflector involving a considerable level of residual reflection. The external resonator-type wavelength tunable laser device includes a planar reflection structure enabling a reflection spectral peak wavelength to be varied and a semiconductor element as a semiconductor gain medium. The semiconductor gain medium is composed of a multiple quantum well in which product &#x393;&#xb7;L of optical confinement constant &#x393; and semiconductor gain medium length L (&#x3bc;m) of a gain layer is at least 25 &#x3bc;m and at most 40 &#x3bc;m and in which gain peak wavelength &#x3bb;0 (nm) observed during carrier injected with a maximum modal gain equal to an internal loss of the semiconductor gain medium is larger than &#x2212;3&#xb7;&#x394;R/2+(&#x3bb;c+35) and smaller than (&#x2212;(&#x393;&#xb7;L)/7+8)&#xb7;&#x394;R+(&#x2212;(&#x393;&#xb7;L)+&#x3bb;c+45). Here, &#x394;R (dB) denotes a reflectance difference, and &#x3bb;c (nm) denotes a wavelength at a center of an operating wavelength range of the wavelength tunable laser device.

External resonator-type wavelength tunable laser device

In an external cavity wavelength tunable laser device including an external cavity () which includes a semiconductor optical amplifier () and performs laser oscillation operation by feeding back external light, a wavelength tunable mirror () having at least a single peak reflection spectrum characteristic within a laser wavelength tuning range is placed on one end of the external cavity (), and a Fabry Perot mode interval determined by the effective length of the external cavity () is not less than 1/10 times and not more than 10 times the reflection band full width half maximum of the wavelength tunable mirror ().

External cavity wavelength tunable laser device and optical output module

In an external cavity wavelength tunable laser device including an external cavity () which includes a semiconductor optical amplifier () and performs laser oscillation operation by feeding back external light, a wavelength tunable mirror () having at least a single-peak reflection spectrum characteristic within a laser wavelength tuning range is placed on one end of the external cavity (), and a Fabry-Perot mode interval determined by the effective length of the external cavity () is not less than 1/10 times and not more than 10 times the reflection band full width half maximum of the wavelength tunable mirror ().

Input ports () formed from fundamental mode waveguides are provided at one end of a multimode waveguide (). Further, an output port () formed from a fundamental mode waveguide is provided at the other end of the multimode waveguide (). The multimode waveguide () has a width wider than those of the input ports () and the output port (), and provides modes including multimode to the waveguide. The multimode waveguide () is embedded with a buried layer (). Both of the end faces of the multimode waveguide () are made to be planes equivalent to a (100) plane or planes inclined from these planes. In a case of inclined planes, the planes are made to be planes inclined to a direction that the waveguide region spreads toward a stacked direction of the semiconductor layers.

Growing community of inventors

Tokyo, Japan

Shinya Sudo