Abstract: A charging controller (300) controls charging of a battery by an interface device (400-1 to 400-m) on the basis of distribution system connection time when the interface device (400-1 to 400-m) and a battery mounted on EV (500-1 to 500-n) are connected to each other and on the basis of distribution system disconnection time when they are disconnected in each of the interface devices (400-1 to 400-m).

Abstract: Charging control section 17 controls charging such that when the charging of an EV satisfies a predetermined condition, the EV is charged with electricity from a stationary energy storage and when the charging of the EV does not satisfy the predetermined condition, the EV is charged with electricity from an electric power grid and information communication grid 1 and the stationary energy storage is charged from electric power grid and information communication grid 1 based on the state of stored electricity of the stationary energy storage. Charging scheduling section 15 performs scheduling for the EV based on an electric power demand that cause electric power grid and information communication grid 1 to charge the EV with electricity, the electric power demand including electric power demand created by charging performed under the control of charging control section 17.

Abstract: A first threshold that is lower than a progressively deteriorating SOC that is an SOC in which a battery performance of the lithium ion secondary battery deteriorates when the lithium ion secondary battery is stored and a second threshold that is greater than the progressively deteriorating SOC are preset.

Abstract: In a predetermined interval, electric power that is generated by power-source equipment is charged to a storage device and the amount of electric power that is accumulated in the storage device is reported from a communication device to a device that is provided to an electric power provider or a consumer. After the passage of a predetermined time interval, the amount of electric power that was previously reported to the device that is provided to the electric power provider or the consumer is discharged from the storage device and supplied to the electric power distribution system.

Abstract: An electric device has an electric power measurement unit with an electric power detection element measuring consumed electric power and an information communication element transmitting the measured power. An electric power meter has an information communication element measuring and transmitting total electric power consumed indoors. An information processing unit stores the measured values in every predetermined sampling period. If a difference ? of two measurement values of the electric power detection element is a finite value, the information processing unit calculates and stores both a difference ? of two measurement values of the electric power meter corresponding to the two measurement values and ?/?, and calibrates the amount of electric power consumed by the electric device and that is measured by the electric power detection element using a median of values of ?/? obtained in a predetermined measurement period or a median of a predetermined number of values of ?/?.

Abstract: An object is to provide a wavelength-tunable laser apparatus that prevents a grid-hopping upon wavelength change, and a wavelength changing method thereof. A wavelength-tunable laser apparatus 101 according to the present invention includes a semiconductor optical amplifier 102 and a periodic wavelength-selection filter 106. Further, the wavelength-tunable laser apparatus 101 includes a phase control unit 111 that concurrently controls a current applied to the semiconductor optical amplifier 102 and a phase tuning of a wavelength-tunable laser under an open-loop control. Thus, dark-tuning can be achieved.

Abstract: An energy system having a plurality of storage batteries and renewable power supplies includes an information processor. Each of the storage batteries is individually set to a maximum SOC representing a charging limit and a minimum SOC representing a discharging limit. Each of the storage batteries is chargeable and dischargeable under the control of an external device and is capable of measuring SOC values. The information processor controls charging and discharging processes of the storage batteries individually to keep the storage batteries charged until SOC values acquired from the storage batteries reach the maximum SOC when the storage batteries are charged and to keep the storage batteries discharged until SOC values acquired from the storage batteries reach the minimum SOC when the storage batteries are discharged.

Abstract: A digital amplifier amplifies an input signal from a tuner (107) which receives a broadcast wave of a set receiving frequency so as to suppress degradation of the high-band reproduction performance and lowering of the amplification efficiency.

Abstract: 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 ?·L of optical confinement constant ? and semiconductor gain medium length L (?m) of a gain layer is at least 25 ?m and at most 40 ?m and in which gain peak wavelength ?0 (nm) observed during carrier injected with a maximum modal gain equal to an internal loss of the semiconductor gain medium is larger than ?3·?R/2+(?c+35) and smaller than (?(?·L)/7+8)·?R+(?(?·L)+?c+45).

Abstract: In an external cavity wavelength tunable laser device including an external cavity (20) which includes a semiconductor optical amplifier (2) and performs laser oscillation operation by feeding back external light, a wavelength tunable mirror (7) having at least a single peak reflection spectrum characteristic within a laser wavelength tuning range is placed on one end of the external cavity (20), and a Fabry Perot mode interval determined by the effective length of the external cavity (20) 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 (7).

Abstract: In an external cavity wavelength tunable laser device including an external cavity (20) which includes a semiconductor optical amplifier (2) and performs laser oscillation operation by feeding back external light, a wavelength tunable mirror (7) having at least a single peak reflection spectrum characteristic within a laser wavelength tuning range is placed on one end of the external cavity (20), and a Fabry Perot mode interval determined by the effective length of the external cavity (20) 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 (7).

Abstract: In an external cavity wavelength tunable laser device including an external cavity (20) which includes a semiconductor optical amplifier (2) and performs laser oscillation operation by feeding back external light, a wavelength tunable mirror (7) having at least a single-peak reflection spectrum characteristic within a laser wavelength tuning range is placed on one end of the external cavity (20), and a Fabry-Perot mode interval determined by the effective length of the external cavity (20) 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 (7).

Abstract: An object is to provide a wavelength-tunable laser apparatus that prevents a grid-hopping upon wavelength change, and a wavelength changing method thereof. A wavelength-tunable laser apparatus 101 according to the present invention includes a semiconductor optical amplifier 102 and a periodic wavelength-selection filter 106. Further, the wavelength-tunable laser apparatus 101 includes a phase control unit 111 that concurrently controls a current applied to the semiconductor optical amplifier 102 and a phase tuning of a wavelength-tunable laser under an open-loop control. Thus, dark-tuning can be achieved.

Abstract: 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 ?·L of optical confinement constant ? and semiconductor gain medium length L (?m) of a gain layer is at least 25 ?m and at most 40 ?m and in which gain peak wavelength ?0 (nm) observed during carrier injected with a maximum modal gain equal to an internal loss of the semiconductor gain medium is larger than ?3·?R/2+(?c+35) and smaller than (?(?·L)/7+8)·?R+(?(?·L)+?c+45).

Abstract: In an external resonator type semiconductor wavelength tunable laser apparatus using a wavelength tunable mirror or a wavelength tunable filter which uses a refractive index change of liquid crystal, a resonant frequency is set as FR, when a response of the refractive index change to a drive voltage frequency of liquid crystal becomes maximum. A frequency F1 of a drive AC power supply voltage to control the refractive index of liquid crystal is set to a frequency largely different from FR. A wavelength tunable mirror or a wavelength tunable filter is driven with a signal in which a dither AC signal F2 of a frequency close to the FR and an AC power supply voltage are superimposed. A PD to monitor a light output from the laser controls an amplitude of the drive AC power voltage such that an amplitude of the dither AC signal F2 become minimum. Thus, high laser mode stability is realized.

Abstract: To facilitate phase adjustment in an external resonator type wavelength-variable laser. An external resonator type wavelength-variable laser (50) includes a semiconductor light amplifier (1), a wavelength selection filter (3) having periodic frequency characteristics, an external resonator (6), and a wavelength-variable filter (4). ?f is divided into one or more regions. The following conditions are satisfied for one ?fi region: mj=(j×?ffs)/?fFP where ?ffs: a period of the wavelength selection filter, ?fFP: a Fabry-Perot mode interval dependent on a length of the external resonator, j: an integer not smaller than 1 and not larger than (?fi/?ffs). A coefficient Mj is an integer obtained by rounding off the first digit after decimal point of the coefficient mj. A coefficient Ni,j is an integer obtained by discarding the first digit after decimal point of ?fi/(j×?ffs). In this regard, a relation of (|Ni,j×2?(Mj?mj)|<?/2) is satisfied for one j.

Abstract: A digital amplifier amplifies an input signal from a tuner (107) which receives a broadcast wave of a set receiving frequency so as to suppress degradation of the high-band reproduction performance and lowering of the amplification efficiency.

Abstract: 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.

Abstract: The reflectance of a semiconductor optical amplifier (1) on the side where an external cavity is formed is 0.1% at most. The finesse value obtained by dividing the period of the transmission characteristic of the wavelength selection filter (3) by the half value width of the transmission characteristic is 4 or more and 25 or less. Even when the reflectance of a cavity side end face (1bb) of the semiconductor optical amplifier (1) is about 0.1%, a wavelength accuracy of ±1.5 GHz can be achieved by setting the finesse to 4 or more. In addition, a wavelength accuracy of about ±0.5 GHz can be achieved by setting the finesse to 8 or more. In order to suppress insertion loss, it is preferable to set the finesse of the FP etalon to 25 or less. This makes it possible to implement an external cavity wavelength tunable laser with high wavelength accuracy.

Abstract: In an external cavity wavelength tunable laser device including an external cavity (20) which includes a semiconductor optical amplifier (2) and performs laser oscillation operation by feeding back external light, a wavelength tunable mirror (7) having at least a single-peak reflection spectrum characteristic within a laser wavelength tuning range is placed on one end of the external cavity (20), and a Fabry-Perot mode interval determined by the effective length of the external cavity (20) 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 (7).