Abstract: A wireless communications system including a mobile station MS and base stations BS1 and BS2, wherein one or both of the mobile station MS and the base stations BS1 and BS2 is provided with a unit for notifying information of a frame position with the possibility of transmission of packets based on detection of deterioration of a reception quality and wherein the mobile station MS is provided with a unit for determining a frame position without the possibility of transmission of packets and shifting to a peripheral cell detection mode at this frame position based on information of a frame position with the possibility of transmission of packets, whereby it is possible to shift to a peripheral cell detection mode without lowering the transmission efficiency and without complicating the processing.

Abstract: A system for wirelessly communicating from a high speed data modem using a first radio transceiver at a first location and a second radio transceiver at a second location preferably includes: (i) a housing (containing the data modem, the first radio transceiver, a radio processor, and a power supply) connected to an outdoor supporting structure, which supports a coaxial cable carrying an RF signal and AC power; (ii) a splitter to split the RF signal from the AC power, wherein the radio processor sends a digital signal to the first radio transceiver, which sends the signal to a first antenna, and wherein the signal is provided from the first antenna to a second antenna coupled to the second radio transceiver at a user device, wherein the system communicates the signal from the second antenna to the second radio transceiver and then to a second radio processor coupled to the user device; and wherein the DC power is provided to the data modem, the first radio transceiver, and the radio processor.

Abstract: The present invention discloses a method for sending signaling and a method for receiving signaling in a multiple carrier frequency communication system. The method for sending signaling comprises: a base station sends control signaling on a primary carrier frequency corresponding to a terminal; the control signaling carries the indication information for indicating the part of control signaling which needs to be decoded of a secondary carrier frequency. The primary carrier frequency is a carrier frequency resource that the terminal must decode all the control signaling. The secondary carrier frequency is a carrier frequency resource on which the terminal can operate determined by the control signaling on the primary carrier frequency of the terminal, and whether the part of the control signaling of the secondary carrier frequency needs to be decoded is indicated by the control signaling of the primary carrier frequency.

Abstract: Aspects of a method and system for WCDMA/HSDPA timing adjustment may include adjusting an uplink transmission timing of a signal for transmission by a large adjustment step, utilizing a plurality of smaller adjustment steps, to generate an adjusted transmission signal. The transmission signal may be upsampled to a rate corresponding to the smaller adjustment step, which may generate an upsampled transmission signal. An adjusted upsampled transmission signal may be generated by inserting one or more of the smaller adjustment steps via one or more extra samples into the upsampled transmission signal to generate a delay, or removing one or more samples from the upsampled transmission signal to generate an advance. The adjusted upsampled transmission signal may be filtered and downsampled to generate the adjusted transmission signal.

Abstract: This invention is a method about frequency multiplex. We employ numbers of sub-carriers whose frequency spectrum are overlapped each other to modulate the transmitted data sequences, and then we get the complex modulated signals. In the receiver point, we make use of one mapping between the overlapped signals' spectrum and the transmitted data sequences to detect the transmitted data sequences. By overlapping the adjacent sun-carriers, this invention can greatly increase the spectrum efficiency, and the more the multiplicity, the higher the spectrum efficiency. Furthermore, when the spectrum efficiency increases, the needed number of signal levels for this invention will not have exponential growth, just linear growth in stead, so the requirement for system linearity can be decreased greatly.

Abstract: Techniques for periodically resetting the polar cap for a differential codebook precoding scheme for wireless communications are described. An apparatus may comprise a fixed device for a mobile broadband communications system utilizing an orthogonal frequency-division multiple access technique, the fixed device having a precoding module operative to generate a precoding matrix using a received first codeword of a first base codebook, subsequently reconstruct the precoding matrix using a received polar-cap codeword of a polar-cap codebook, and periodically reset the precoding matrix to clear accumulated error at the fixed device using a received second codeword of a second base codebook. Other embodiments are described and claimed.

Abstract: The present application provides methods, devices and transmitters that mitigate increases in peak to average power ratio (PAPR) from transmission diversity in a single carrier frequency division multiple access (SC-FDMA) modulated uplink A PAPR preserving precode matrix hopping method that utilizes cyclic shift delays is provided, as well as a sub-band based transmit diversity scheme. The present application also provides methods, devices and transmitters that relax the scheduling restrictions associated with uplink scheduling in the LTE standard.

Abstract: A relay device that relays a message transmitted from a terminal device to a server through a communications network. When a message is received from the terminal device, the relay device obtains attribute information related to the user of the terminal device, obtains an identifier to be inserted into a message to the terminal device by a server that generated a session in response to the message from the terminal device, the identifier being for identifying the session, stores the obtained identifier that is associated with the attribute information, determines whether or not the attribute information coincident to the attribute information obtained by receiving the message from the terminal device is to be stored when a message was received from the terminal device, inserts the identifier associated with the attribute information into the message received from the terminal device when the coincident attribute information is stored, and relays the message.

Abstract: Systems, methods, and computer program products are provided for manual ring-down communication using Session Initiation Protocol (SIP). A first SIP user agent transmits a message to a second SIP user agent over an Internet Protocol (IP) network to establish a SIP session. The first SIP user agent determines that a signal key associated with a first communication device has been selected and transmits, to the second SIP user agent over the IP network, a start event message to cause a second communication device to activate an alert. The first SIP user agent determines that the signal key has been released and transmits over the IP network an end event message to deactivate the alert. The first SIP user agent transmits, to the second SIP user agent over the IP network, one or more subsequent INVITE messages at a predetermined repetition rate to refresh the SIP session.

Abstract: Described are a method, a computer program product and apparatus for implementing signaling gateway redundancy. A first SIGTRAN protocol application server process maintenance message is received, at a first signaling gateway, from a first application server process. Connection control information associated with one or more connections to the first signaling gateway is updated based on the first SIGTRAN protocol application server process maintenance message. A second SIGTRAN protocol application server process maintenance message is transmitted, from the first signaling gateway, to a second signaling gateway. The second SIGTRAN protocol application server process maintenance message is based on the first SIGTRAN protocol application server process maintenance message. The second signaling gateway is mated with the first signaling gateway.

Abstract: Call placement to or from satellite UEs is optimized by reducing IMS message exchanges, the originating party has control over QoS parameters; a HPA subscription service is made available, and calls to a terminating satellite UE that is shielded from satellite coverage are completed by selectively employing HPA pages. For a call request without preconditions, an IMS node associated with an originating UE uses the NRSCPA on Offer instead of using the standard terminating node initiated NRSCPA on Answer. An IMS node associated with a terminating UE checks for HPA subscription by the user. If subscribed, the terminating INVITE request is for a “Conversational” or “Interactive” service, and the terminating UE is in PMM_IDLE state, the satellite RAN pages the terminating UE using HPA.

Abstract: A circuit arrangement, network-on-chip, and a method for transmitting information are disclosed. In one embodiment, an electrical circuit is provided comprising a plurality of circuit blocks comprising a first circuit block, a second circuit block, and a third circuit block, and a connection structure coupled to the plurality of circuit blocks, wherein the first circuit block is configured to send a request comprising information corresponding to the request and an address onto the connection structure, wherein the second circuit block is configured to initiate a transmission onto the connection structure in response to receiving the request, and wherein the third circuit block is configured to receive the transmission and wherein the address is assigned to the third circuit block.

Abstract: In a particular embodiment, a method of providing multimedia communication services includes receiving, at an intelligent service switch (ISS) of an integrated wireline-wireless (IWW) network, a service request from a wireline communication device. The method includes receiving contextual information associated with the service request, the contextual information including a time of the service request, a range of times of the service request, a day of the service request, a range of days of the service request, a date of the service request, a range of dates of the service request, a location of the wireline communication device, a type of the wireline communication device, or a combination thereof. At least one multimedia communication service is provided to the wireline communication device.

Abstract: A single IMPI is determined, allowing the progress of a terminating call that addresses a given IMPU shared by more than one IMPI of an IMS subscription. A number of policies are applied per IMPI basis on how to progress the terminating call. A HSS is provided where the policies are configured and, a method is disclosed including IMPU with a number of policies. Additionally, the method may also include a step of configuring at the HSS the more than one IMPI with a priority indication usable to set the order in which the more than one IMPI are checked to determine at least one for which the policies allow to progress the terminating call.

Abstract: Techniques for inserting a new node into a communications path of existing nodes of a 3GPP network are described herein. According to one embodiment, state information is captured within a transport protocol layer of a first node. The state information pertains to an existing communications session between a second node and a third node, while the first node routing packets exchanged between the second and third nodes via the existing communications session. The transport protocol layer of the first node is then configured using the captured state information to enable the transport protocol layer of the first node to independently communicate with a transport protocol layer of the second node and the third node respectively without terminating the existing communications session.

Abstract: The invention relates to a telecommunication system featuring partly CS-based telecommunication and partly PS-based telecommunication. A dynamic controller is provided for making allocations between the parts, taking into account access network requests. A corresponding method and a computer program for implementing the controller are also claimed.

Abstract: The invention reduces addressing overhead for communication using a layered communication protocol. An improvement of the invention maintains security for the addressing information.

Abstract: A system allowing for path monitoring and notification in a system of switching elements and processing elements is provided. An exemplary technique uses a monitoring and notification module configured to generate and output monitoring messages across multiple paths defined by the plurality of switching elements and the plurality of processing elements, detect a fault in the system based on the monitoring messages, and generate and output multiple alert messages across the multiple paths to initiate recovery from the fault As such, a single element (or group of elements) does not become isolated from the rest of the elements in the system.

Abstract: A method and system for multicasting Internet-protocol television (IPTV) channels is disclosed. In order to receive desired IPTV channels, a first-hop router (FHR) may send a join message to a last-hop router (LHR) establishing multiple paths across a backbone network. The join message may specify mapping at least one virtual IPTV channel to a plurality of multicast channels, along with the desired IPTV channels. The multicast channels may then be transmitted in a round-robin manner over the multiple paths from the LHR to the FHR. A number of virtual IPTV channels may be modified in response to determining a loading profile over the multiple paths to maintain a balanced load among the multiple paths.

Abstract: Methods and systems for implementing private allocated networks in a virtual infrastructure are presented. One method operation creates virtual switches in one or more hosts in the virtual infrastructure. Each port in the virtual switches is associated with a private allocated network (PAN) from a group of possible PANs. In one embodiment, one or more PANs share the same physical media for data transmission. The intranet traffic within each PAN is not visible to nodes that are not connected to the each PAN. In another operation, the method defines addressing mode tables for the intranet traffic within each PAN. The entries in the addressing mode tables define addressing functions for routing the intranet traffic between the virtual switches, and different types of addressing functions are supported by the virtual switches.

Abstract: A method and a system for transferring a PIM-address in an electronic formula of a PIM-application, based on a communication connection between end devices of subscribers in a communication system are provided. A communication system address, which identifies the second end device, detects user input of a first subscriber. The detected communication system-address is converted into a PIM address which identifies a second subscriber, the PIM-address to the PIM-application and the transferred PIM-address is input into a field of the electronic formula of the PIM-application.

Abstract: Autoconfiguration of an IPv6 component in a segmented network including receiving an IPv6 packet; determining whether the received IPv6 packet is a router advertisement or a router solicitation; if the received IPv6 packet is a router advertisement, then retrieving through an out-of-band link a MAC address for the IPv6 component, removing a MAC address of a sending router, inserting in the packet instead an internal MAC address for forwarding packets to the IPv6 component, removing a multicast destination MAC address, inserting in the packet the destination MAC address of the IPv6 component, and forwarding the packet to the IPv6 component as a unicast message; if the received IPv6 packet is a router solicitation, then removing the MAC address of the sending IPv6 component, inserting in the packet instead an external MAC address for forwarding packets to the router, and forwarding the packet to the router as a multicast message.

Abstract: Various embodiments relate to a Cloud Data Center, a system comprising the Cloud Data Center, and a related method. The Cloud Data Center may include a logical customer edge router to send packets between addresses in a private enterprise network and addresses in a logical network within a cloud network using Layer 2 protocol and MAC addressing. The logical network may have resources, known as virtual machines, allocated to the private enterprise network and may share a common IP address space with the private enterprise network. A directory at the Cloud Data Center may correlate the enterprise IP addresses of virtual machines with a MAC address, cloud IP address, and a location IP address within the logical network. The Cloud Data Center may double encapsulate packets with MAC, cloudIP, and locIP headers, when sending a packet to a destination in the logical network.

Abstract: A communication system for performing communication based on the Real-time Transport Protocol/RTP Control Protocol (RTP/RTCP) comprises a communication control device, a first NAT device and a second NAT device, a caller terminal device, and a callee terminal device. The caller terminal device transmits a first packet to the communication control device, receives a second packet that contains a second port number that is stored in the second NAT device, determines whether the second port number is one of an odd number and an even number; and transmits, in a case where it has been determined that the second port number is an odd number, an RTP packet to a port number that is computed by adding 2n?1 to the second port number, then transmits an RTCP packet to a port number that is computed by adding 2n to the second port number.

Abstract: A telecommunications system includes a first node having audio and video streams. The system includes a second node having only an audio stream. The system includes a mechanism for forming a call between the first node and the second node so the first node and the second node communicate their audio streams with each other. The forming mechanism is in communication with the first and second nodes. Preferably, a third node can communicate with the first and second nodes through the forming means. A method for forming a telecommunications call including the steps of calling from a first node having audio and video streams a second node having only an audio stream. There is the step of forming a call between the first node and the second node so the first node and the second node communicate their audio streams with each other.

Abstract: Systems, modules, computer-readable mediums and methods for multi-layer interworking are provided. An identified traffic path is selected from one or more traffic paths. The identified traffic path is selected based on information indicative of traffic path parameter information associated with the identified traffic path relative to traffic path parameter information associated with the other traffic paths. A transport trail is identified from one or more transport trails. Whether the identified transport trail from one or more transport trails is suitable for assignment is determined. The determination is made based on information indicative of the transport trail parameter information associated with the identified transport trail relative to transport trail parameter information associated with the other transport trails. The selected identified traffic path is assigned to the identified transport trail if the identified transport trail is determined to be suitable for assignment.

Abstract: Methods, systems, and computer program products for providing dynamic Quality of Service (QoS) for connections to applications over a network are provided. The method receives a message associated with the application, wherein the message includes information identifying the connection to the application and information about the application. The method then determines, based on a set of rules defined for the application, a QoS level to apply to the connection, and applies the determined QoS level to the connection. The QoS applied to the connection corresponds to the application and not the QoS associated with a personal or home account QoS that would otherwise be applied to the connection.

Abstract: Methods, systems, and products provide communications services. A request for communications service is received at a service provider and a best-value scenario is determined. Packets of data are subcontracted to another service provider to receive a subcontracted processing service. A result of the subcontracted processing service is incorporated in the best-value scenario, and the communications service is provided to fulfill the request for communications service.

Abstract: Methods and apparatus for distribution of IP layer routing information in peer-to-peer overlay networks. A method includes transmitting an advertisement to a first subnet advertising the accessibility of subnets and including unique subnet identifiers to disambiguate overlapping addresses, receiving a request from a network that includes the first subnet to communicate with a network that includes the second subnet, establishing a first tunnel with the second subnet and a second tunnel with the first subnet, and directing transmissions between the tunnels based on policy. An apparatus includes means for transmitting the advertisement, means for receiving a request, means for establishing the first tunnel with the second subnet and the second tunnel with the first subnet, and means for directing transmissions between the first and second tunnels based on policy information.

Abstract: Various embodiments relate to a Cloud Data Center, a system comprising the Cloud Data Center, and a related method. The Cloud Data Center may include a logical customer edge router to send packets between addresses in a private enterprise network and addresses in a logical network within a cloud network. The logical network may have resources, known as virtual machines, allocated to the private enterprise network and may share a common IP address space with the private enterprise network. A directory at the Cloud Data Center may correlate the enterprise IP addresses of virtual machines with a cloud IP address and a location IP address within the logical network. The Cloud Data Center may double encapsulate packets with two specified headers, a cloudIP and locIP header, when sending a packet to a destination in the logical network.

Abstract: As the proliferation of data rich content and increasingly more capable mobile devices has continued, the amount of data communicated over mobile operator's networks has increased. Upgrading the existing network that was designed for voice calls is not desirable or practical for many mobile operators. This disclosure relates to a mobility edge gateway that resides on the edge of the core network and can provide one or more services such as call localization, offloading of traffic, session management, and content streaming. The call localization involves identifying calls that can be maintained at the edge of the network and bridging the calls at the mobility edge gateway to bypass the core network. The offloading involves identifying traffic and offloading the traffic to the Internet or another network to bypass the core network. These services can relieve congestion on the core network of mobile operator's networks.

Abstract: A system and method for managing multimedia messaging is described. A system includes a messaging intermediation module having, a sender-side interface configured to communicate a multimedia message between the messaging intermediation module and a data gateway of a multimedia messaging system, a recipient-side interface configured to communicate the multimedia message between the messaging intermediation module, an Internet gateway, a message store and forward (MSF) server, and another messaging intermediation module, a message storage module configured to store the multimedia message for forwarding to the Internet gateway, the MSF server, and the other messaging intermediation module, and a workflow engine configured to process the multimedia message. In response to the processing, the workflow engine forwards the multimedia message to the Internet gateway, forwards the multimedia message to the MSF server, or forwards the multimedia message to the other messaging intermediation module.

Abstract: A network gateway for time-critical and mission-critical networks is provided. The network gateway comprises a decision unit for determining, based on at least one network event; a processing unit for processing frames determined to be associated with the at least one service; a queue for buffering frames; and a traffic shaper for performing bandwidth management on frames stored in the queue.

Abstract: A network interface system for transferring a data packet between a host system and a network includes multiple matchers and multiple queues. The matchers match the data packet with multiple rules from the host system to generate multiple matching results and allocate a transferring priority to the data packet according to the rules. The queues correspond to the matchers respectively. A queue of the queues stores information indicating the transferring priority for the data packet according to the matching results and priorities of matchers.

Abstract: Provided are a packet transmission device and a packet transmission method which can effectively use a radio band while suppressing a processing overhead. A packet transmission device (100) includes: a transmission path judgment unit (110) which judges a transmission path state according to a radio channel quality estimation result; and an adaptive scheduler unit (108) which includes a low QoS packet into a transmission frame constituent element with a higher priority if the transmission path state is judged to be bad and a high QoS packet into the transmission frame constituent element with a higher priority if the transmission path state is judged to be good. That is, the adaptive scheduler unit (108) allocates a low QoS packet with a higher priority when it is judged that the possibility of generation of a radio error is high and the transmission path state is bad.

Abstract: A filtered Forwarding Information Base (FIB) (the “complete local FIB”) is used to determine how to forward packets, typically on line cards. The complete local FIB is generated by filtering (i.e., dropping or removing) extraneous entries in the standard global FIB of a router. This smaller FIB is then installed within the memory of a forwarding engine, possibly implemented as a single application-specific integrated circuit (ASIC), for use in determining how to forward packets, with the router forwarding packets accordingly.

Abstract: A data communication bus and method of operation thereof, including a plurality of nodes connected to a respective plurality of media segments. A typical node includes an output port coupled to a media segment that it exclusively controls. And an input port coupled to a media segment that is exclusively controlled by another node of the bus. Each media segment typically includes a plurality of high speed data channels such as electrical transmission lines.

Abstract: Embodiments of the invention are generally directed to messaging to provide data link integrity. An embodiment of a method includes transmitting a data stream over a data link from a first device to a second device, the data stream including multiple frames, the data stream being transmitted in a first mode. The method further includes determining a data transmission mode change from the first mode to a second mode for the transmission of the data stream from the first device to the second device, generating mode packets, each mode packet including fields to define a plurality of mode elements, the fields of the mode packet being set to indicate the data transmission mode change, and transmitting the mode packets to the second device prior to implementing the data transmission mode change.

Abstract: A communication system processes blocks of input data that include control words and a packet of information words are received. The packet has a start preceded by ones of the control words and an end followed by others of the control words. When the block consists exclusively of information words, a one bit block header having a first sense is appended to the block to form a frame. When the block does not consist exclusively of information words, the block is condensed to accommodate a TYPE word, the TYPE word is generated and inserted into the block and a one bit block header is appended to the block to form the frame. When the block does not consist exclusively of information words the one bit block header has a second sense, opposite to the first sense. Use of a one bit block header reduces overhead. Forward error correction is also utilized.

Abstract: A method includes composing downlink control information having a format configured to support a presence of a plurality of transport blocks in a single subframe, where the downlink control information comprises, for the plurality of transport blocks, a common resource allocation and modulation/coding scheme field and a single cyclic redundancy check field. The method further includes transmitting the composed downlink control information to a relay node over a wireless link that comprises a backhaul link from the relay node.

Abstract: A method, apparatus, and system for time synchronization are disclosed. The method comprising: obtaining a master sending time stamp, a slave receiving time stamp, a slave sending time stamp, and a master receiving time stamp; and adjusting the time of the slave clock according to the offset calculated from the time stamps to synchronize with the clock time of the master clock. With the present invention, in passband transmission systems that transmit signals continuously in units of symbols, the time synchronization is implemented between the master clock and the slave clock.

Abstract: Methods and systems for generating high energy, mode locked, femtosecond and picosecond laser pulses are disclosed, including generating electromagnetic radiation from a pump laser; coupling the electromagnetic radiation to a rare Earth doped fiber using a pump/signal coupler; coupling the output from the rare Earth doped fiber to a first fiber; coupling a bandpass filter to the first fiber output and to a second fiber; coupling a first in-line polarization controller to the second fiber output and an in-line polarization beam splitter comprising a non-polarization maintaining fiber output and a polarization maintaining fiber output configured to emit an output laser pulse; coupling a polarization insensitive isolator to the non-polarization maintaining fiber output of the in-line polarization beam splitter and to a second in-line polarization controller; coupling a third fiber output to the second in-line polarization controller and to the pump/signal coupler. Other embodiments are described and claimed.

Abstract: A laser comprises an end pump light source and a gain medium having a first end, a second end, and four sides comprising a first, a second, a third, and a fourth side. The end pump light source is optically coupled to the first end and pumps the gain medium. The first side and the third side are tapered inwardly from the first end to the first end to the second end at a taper angle ? relative to a longitudinal lasing axis and have a polished finish capable of reflecting light inside the gain medium. The second side and the fourth side are substantially parallel to the longitudinal lasing axis have a ground blasted finish. The first side is also tilted inwardly at a slant angle ? from the fourth side to the second side. A laser beam R0 exits the second end of the gain medium.

Abstract: The configurations of an electro-optic Bragg deflector and the methods of using it as a laser Q-switch in a Q-switched laser and in a Q-switched wavelength-conversion laser are provided. As a first embodiment, the electro-optic Bragg deflector comprises an electrode-coated electro-optic material with one of a 1D and a 2D spatially modulated electro-optic coefficient. When a voltage is supplied to the electrodes, the electro-optic material behaves like a Bragg grating due to the electro-optically induced spatial modulation of the refractive index. The second embodiment relates to an actively Q-switched laser, wherein the electro-optic Bragg deflector functions as a laser Q-switch. The third embodiment of the present invention combines the Q-switched laser and a laser-wavelength converter to form a Q-switched wavelength-conversion laser, wherein the EO Bragg deflector can be monolithically integrated with a quasi-phase-matching wavelength converter in a fabrication process.

Abstract: A tuning methods of an External Cavity Laser Diode (ECLD), comprises steps of: (1) providing a laser light to a grating so as to tilt the grating to an optical axis of a collimated laser light, (2) adjusting the orientation of the grating relative to the collimated laser light, (3) monitoring singleness of longitudinal mode and optical power of a light emitted from the grating, (4) calculating an orientation of the grating to exhibit intended optical power at which the singleness of longitudinal mode shows at least predetermined value, (5) adjusting the grating orientation or the optical axis of the collimated laser light to the calculated grating orientation.

Abstract: Structures and techniques are disclosed that enable efficient generation of terahertz (THz) radiation capable of surpassing the fundamental quantum limit, as defined by the Manley-Rowe relations. In one particular embodiment, a difference frequency mixing (DFM) crystal stage receives pump radiation and signal radiation, and generates THz radiation. Leftover signal radiation from the DFM stage is then used to pump an optical parametric oscillator (OPO) stage, which is used to generate another mixing signal and more THz radiation. The output signal and the residual pump from the OPO stage can then be used in a subsequent DFM process to generate even more terahertz radiation, and further drives a subsequent OPO stage. Such cascaded OPO, DFM, OPO staging can be repeated to maximize total amount of THz output power.

Abstract: A correction circuit is provided, which may reduce dullness of a light output waveform due to wavelength detuning. The correction circuit includes an RC time constant circuit. The RC time constant circuit is used to correct a waveform of a current pulse outputted from a current source, the current source driving a surface-emitting semiconductor laser in a pulsed manner, so that a pulse waveform of light output of the semiconductor laser is approximately a rectangle.

Abstract: The present invention relates to an atomic frequency acquisition device comprising a gas cell (400) filled with an atomic gas, a laser light source (100) emitting a laser beam which enters the gas cell (40) and excites a first energy transition of the atomic gas, a local oscillator (700) for generating an oscillator frequency in a frequency range including a frequency of a HFS transition of the atomic gas, and a modulator (600) modulating the laser light source (100) so as to emit laser radiation modulated with the oscillator frequency. An optical reflector (500) is arranged behind the gas cell (400) to reflect the laser beam after passage through the atomic gas so as to re-enter the laser cavity. A photodetector (200) detects beat frequencies caused by self-mixing interference within the laser cavity.

Abstract: The present invention provides a semiconductor laser realizing reduced possibility that a wiring layer disposed in the air is broken even under severe environment of a large temperature difference. A trench is provided between adjacent ridges, and a wiring layer electrically connecting an upper electrode and a pad electrode is disposed in the air at least above the trench. The wiring layer in a portion above the trench has a flat shape or a concave shape which dents toward the trench. With the configuration, accumulation of strains in the wiring layer when the wiring layer repeats expansion and shrink under severe environment of a large temperature difference is suppressed.

Abstract: In a III-nitride semiconductor laser device, a laser structure includes a support base with a semipolar primary surface comprised of a III-nitride semiconductor, and a semiconductor region provided on the semipolar primary surface of the support base. First and second dielectric multilayer films for an optical cavity of the nitride semiconductor laser device are provided on first and second end faces of the semiconductor region, respectively. The semiconductor region includes a first cladding layer of a first conductivity type gallium nitride-based semiconductor, a second cladding layer of a second conductivity type gallium nitride-based semiconductor, and an active layer provided between the first cladding layer and the second cladding layer. The first cladding layer, the second cladding layer, and the active layer are arranged in an axis normal to the semipolar primary surface.