Abstract: An acoustic signal receiving apparatus including: a Fabry-Perot sensor including a Fabry-Perot interferometer configured to convert an acoustic wave into a light intensity signal; a control unit configured to set a first wavelength and a second wavelength; a detecting unit configured to convert light intensities obtained by irradiation of the Fabry-Perot sensor with light from the first light source and the second light source into electric signals; and a signal processing unit configured to acquire a difference between an electric signal corresponding to the first wavelength and an electric signal corresponding to the second wavelength, wherein the control unit is configured to set the first wavelength and the second wavelength so that differential values of reflectivity spectrum of the Fabry-Perot sensor are different at the first wavelength and the second wavelength.

Abstract: An acoustic wave acquiring apparatus is used that includes: an array light source including a plurality of elements emitting measurement light; a controller controlling the wavelength of the measurement light, for each of or the plurality of elements; a Fabry-Perot interferometer including a first mirror upon which the measurement light is incident and a second mirror upon which an acoustic wave from a subject is incident; an optical sensor measuring a light quantity of reflected light by the first and the second mirror; and a processor acquiring an intensity of the acoustic wave on the basis of a change of the light quantity of the reflected light, which is a distance between the first mirror and the second mirror, occurring due to the incidence of the acoustic wave.

Abstract: Provided is a photonic device in which emission intensity in a short wavelength region is suppressed even in the case of increasing carrier injection density so as to obtain a wide spectrum half-maximum width as well as a high output. The photonic device includes: a first cladding layer; a second cladding layer; and an active layer including an emitting layer and a barrier layer and being provided between the first cladding layer and the second cladding layer, the emitting layer emitting light in a spectrum having a center wavelength ?c and a spectrum half-maximum width ??, in which at least one of the first cladding layer and the second cladding layer includes a light absorbing part for absorbing light having a wavelength of ?s or less represented by the following Expression (1): ?s<(?c?(??/2))??(1).

Abstract: A light-emitting element array includes light-emitting elements that emit light in a direction perpendicular to a substrate. Each light-emitting element includes the substrate, a first nitride semiconductor layer on the substrate and having a mesa portion, an active layer made of a nitride semiconductor disposed on the surface of the mesa portion of the first semiconductor layer opposite the substrate, a second nitride semiconductor layer on the active layer, and a heat radiation layer disposed so that the surface formed by projecting the heat radiation layer on a plane perpendicular to the optical axis of the light-emitting element does not overlap with the surface formed by projecting the mesa portion on the same plane when viewed in the optical axis direction. When the light-emitting element is projected on a plane perpendicular to the optical axis, the surface has an area in a specific range.

Abstract: A light source system includes a laminate having a lower electrode layer, an active layer and an upper electrode layer in this order, a light-emitting element including at least one of the upper electrode layer and the lower electrode layer divided into a plurality of electrodes and configured to emit light by injecting a current into the active layer via the upper electrode layer and the lower electrode layer, and a control unit configured to control a current injecting amount to the upper electrode layer and the lower electrode layer. The control unit controls a half-value width of the emission spectrum of the light-emitting element by varying a difference between an injection current density to a first electrode and an injection current density to a second electrode among the plurality of electrodes.

Abstract: A light source includes an upper electrode layer, a lower electrode layer, and an active layer interposed therebetween. At least one of the upper and lower electrode layers is divided into a plurality of electrodes separated from each other in an in-plane direction of the active layer. The separated electrodes independently inject current into a plurality of different regions in the active layer. The light source emits light by injecting current from the upper and lower electrode layers into the active layer, guide the light in the in-plane direction, and output the light. The plurality of different regions in the active layer include a first region not including a light exit end and a second region including the light exit end, and the second region is configured to emit light of at least first-order level. The active layer has an asymmetric multiple quantum well structure.

Abstract: A superluminescent diode which amplifies light through stimulated amplification and outputs emitted beams from one of edges at two ends includes a cladding layer of a first conductivity type formed on a semiconductor substrate, an active layer formed on the cladding layer of the first conductivity type, a cladding layer of a second conductivity type formed on the active layer, and a multilayer film formed at the other edge opposite to the one edge that emits the beams, reflectance of which has wavelength dependence, and a spectral shape of the emitted beams output from the one edge is controllable by the multilayer film.

Abstract: Even if requirements for any scale of system constructions occur, a battery system of flexibly responding to the requirements is provided. The battery system comprising a battery module having a plurality of battery cells being connected, a battery pack having a plurality of battery modules being connected either in series or in parallel or both in series and in parallel, and a battery block having a plurality of battery packs being connected either in series or in parallel or both in series and in parallel. They are mutually layered. In the battery system, the battery module, the battery pack, and the battery block are previously prepared as variations of layered basic units. In response to requirements for any scale of system constructions, the basic units are combined accordingly.

Abstract: A surface emitting laser includes a lower reflector, an active layer, a gap portion, and an upper reflector, which are arranged in that order, and a driving unit. The surface emitting laser is capable of varying a wavelength of emitted light by changing a distance between the upper and lower reflectors. The driving unit moves one of the upper and lower reflectors in an optical axis direction of the emitted light. When ?g is a wavelength at which a gain at a time of laser oscillation of the active layer is at a maximum, ?0 is a center wavelength of the emitted light, and ?r is a wavelength at which a reflectance of one of the upper and lower reflectors from which the light is emitted is at a maximum, ?r<?o<?g or ?g<?o<?r is satisfied.

Abstract: A light-emitting element array includes light-emitting elements that emit light in a direction perpendicular to a substrate. Each light-emitting element includes the substrate, a first nitride semiconductor layer on the substrate and having a mesa portion, an active layer made of a nitride semiconductor disposed on the surface of the mesa portion of the first semiconductor layer opposite the substrate, a second nitride semiconductor layer on the active layer, and a heat radiation layer disposed so that the surface formed by projecting the heat radiation layer on a plane perpendicular to the optical axis of the light-emitting element does not overlap with the surface formed by projecting the mesa portion on the same plane when viewed in the optical axis direction. When the light-emitting element is projected on a plane perpendicular to the optical axis, the surface has an area in a specific range.

Abstract: A surface emitting laser includes a lower reflector, an active layer, a gap portion, an upper reflector, and a driving unit. The lower reflector, the active layer, the gap portion, and the upper reflector are arranged in that order. The surface emitting laser is capable of varying a wavelength of emitted light by changing a distance between the upper and lower reflectors. The driving unit moves one of the upper and lower reflectors in an optical axis direction of the emitted light. At least one of the upper and lower reflectors includes a stacked body in which first layers and second layers are alternately stacked, the second layers having a refractive index lower than a refractive index of the first layers, outermost layers of the stacked body being the first layers, and a third layer provided on at least one end of the stacked body.

Abstract: Provided is a wavelength-variable laser including an SOA which controls not a shape of a gain spectrum itself in the SOA but a shape of a gain spectrum obtained in the entire SOA to enable inhibition of output fluctuations. The wavelength-variable laser including an SOA includes: a wavelength selection mechanism for selectively reflecting a wavelength; an SOA for amplifying light, the SOA being configured to reflect light that enters a first end facet by a second end facet opposite to the first facet and to cause light amplified in an active layer to exit from the first facet; and a reflecting member provided outside the SOA, the reflecting member forming a resonator in a pair with the second facet, in which the second facet has a multilayer film to control of a shape of gain spectrum obtained in the entire SOA, the multilayer film having a reflectance depending on wavelength.

Abstract: A light emitting device includes an optical waveguide including an active layer having at least two gain peaks and a pair of clad layers sandwiching the active layer and electrodes disposed in a guided wave direction of the optical waveguide. The electrodes include a first electrode nearest the emitting end and a second electrode next thereto. The light emitting device includes a grating section in the vicinity of the optical waveguide between the first and second electrodes. The grating section reflects or absorbs a beam having a wavelength other than peak wavelengths corresponding to the two gain peaks in a spectrum of the beam generated by driving the second electrode. The beam generated by driving the second electrode and having the selected wavelength is guided to a region of the optical waveguide where the first electrode is disposed and is combined with a beam generated by driving the first electrode.

Abstract: A method of manufacturing a surface-emitting laser that allows precise alignment of the center position of a surface relief structure and that of a current confinement structure and formation of the relief structure by means of which a sufficient loss difference can be introduced between the fundamental transverse and higher order transverse mode. Removing the dielectric film on the semiconductor layers and the first-etch stop layer along the second pattern, using a second- and third-etch stop layer are conducted in single step after forming the confinement structure. The relief structure is formed by three layers including a lower, middle and upper layer, and total thickness of three layers is equal to the optical thickness of an odd multiple of ¼ wavelength (?: oscillation wavelength, n: refractive index of the semiconductor layer). The layer right under the lower layer is the second-etch stop layer and the first-etch stop layer is laid right on this etch stop layer.

Abstract: An image forming apparatus improved in the accuracy of detecting a time period over which a laser beam is scanned. A laser beam emitted from a laser light source is deflected by a polygon mirror such that the laser beam scans a photosensitive drum. The deflected laser beam is guided onto the photosensitive drum via an imaging lens. A mode hop detection unit detects a mode hop of the laser beam. An image pulse generation section detects a main scanning magnification of an electrostatic latent image formed on the photosensitive drum. When a mode hop is detected, the main scanning magnification in a next scanning cycle is corrected using a correction value stored in a storage unit and used most lately, whereas when no wavelength variation has not detected, the main scanning magnification in the next scanning cycle is corrected using the latest correction value.

Abstract: A light source apparatus includes a surface emitting laser including a movable mirror, a mirror arranged opposite to the movable mirror, and an active layer arranged between the two mirrors, a mirror driving unit configured to move the movable mirror to a position where laser oscillation is not performed, a laser driving unit configured to inject current into the surface emitting laser, a storage unit configured to store position information of the movable mirror, the position information including a mirror position where laser oscillation is not performed and a mirror position where laser oscillation is performed, and a control unit configured to control the laser driving unit and to determine start timing of the current injection into the surface emitting laser according to the position information output from the storage unit.

Abstract: A drive control method of an SD-OCT system which includes a light source including an SLD, which is a superluminescent diode, and a drive control unit that drive-controls the SLD, and a spectroscope including a linear sensor, and performs a spectroscopic process on returned light, which is emitted from the light source and passes through a reference optical system and an irradiation optical system, by using the spectroscope and obtains an optical coherence tomographic image based on spectrum information of light obtained by the spectroscopic process. When the drive control unit generates a drive waveform having three or more current values and periodically changes the drive waveform to one of the current values, the period is set to an integer multiple of a period in which the linear sensor acquires the spectrum information and a spectral shape is controlled to be a shape required by the SD-OCT system.

Abstract: Provided are a metal-polishing liquid that comprises an oxidizing agent, an oxidized-metal etchant, a protective film-forming agent, a dissolution promoter for the protective film-forming agent, and water; a method for producing it; and a polishing method of using it. Also provided are materials for the metal-polishing liquid, which include an oxidized-metal etchant, a protective film-forming agent, and a dissolution promoter for the protective film-forming agent.

Abstract: When detecting a fault of a master control device, a slave control device refers to master-device-line information, and obtains line information to establish a connection with the other master control device. The slave control device transmits connection request information to the master control device extracted from the other master control devices. The other master control device determines whether or not it is connectable with the slave control device that has transmitted the connection request information, and transmits a determination result as connectability information. The slave control device switches a communication line to the other master control device when the received connectability information indicates the connectable status.

Abstract: An acoustic signal receiving apparatus including: a Fabry-Perot sensor including a Fabry-Perot interferometer configured to convert an acoustic wave into a light intensity signal; a control unit configured to set a first wavelength and a second wavelength; a detecting unit configured to convert light intensities obtained by irradiation of the Fabry-Perot sensor with light from the first light source and the second light source into electric signals; and a signal processing unit configured to acquire a difference between an electric signal corresponding to the first wavelength and an electric signal corresponding to the second wavelength, wherein the control unit is configured to set the first wavelength and the second wavelength so that differential values of reflectivity spectrum of the Fabry-Perot sensor are different at the first wavelength and the second wavelength.