Abstract: A cartridge assembly for a data storage disk includes a housing for containing the data storage disk inside the housing. The housing defines a plurality of openings for exposing a portion of the data storage disk. An external shutter is supported by the housing on the outside of the housing. The external shutter is moveable between a closed position and first and second open positions disposed on opposite sides of the closed position. According to another aspect, a cartridge assembly for a data storage disk includes a casing and a moveable member disposed to slide on the casing. At least one of the casing and the moveable member includes protrusions or equivalent structure for holding the moveable member in a closed position and in one or more open positions. A method of making a ready-to-use data storage disk cartridge assembly provides other advantages.

Abstract: A head support mechanism includes a slider for carrying a head at least for performing reproduction of data from a disk, and a holding portion for holding the slider. The holding portion includes: a first portion including a first piezoelectric element; a second portion including a second piezoelectric element; a third portion connected to the first and second portions, the slider being provided on the third portion; and fixing portion for fixing the first and second portions. At least one of the first and second piezoelectric elements is contracted and expanded in a direction substantially parallel to a surface of the disk, in the presence of an applied voltage so that the slider provided on the third portion is rotated around a predetermined center of rotation.

Abstract: Data cells traversing an Asynchronous Transfer Mode (ATM) network (10) are passively monitored by probes at two spaced points (12,14). A filtering characteristic is applied to select cells comparatively infrequently, and timestamps or sequence numbers (or both) for the cells selected at each point are forwarded to a correlator (28). The correlator identifies similarities in the temporal patterns of intervals between timestamps received from each probe, and uses these similarities to identify and correlate timestamps relating to occurrence of the same cell at the two monitored points. The correlated timestamps are used to determine parameters indicative of the performance of the network, such as one-way delay, variation in that delay, and rate of cell loss.

Abstract: A method for managing data traffic in nodes in a fabric network, each node having internally-coupled ports, follows the steps of establishing a managed queuing system comprising one or more queues associated with each port, for managing incoming data traffic; and accepting or discarding data directed to a queue according to the quantity of data in the queue relative to queue capacity. In one preferred embodiment the managed system accepts all data directed to a queue less than full, and discards all data directed to a queue that is full. In some alternative embodiments the queue manager monitors quantity of data in a queue relative to queue capacity, and begins to discard data at a predetermined rate when the quantity of queued data reaches the threshold. In other cases the queue manager increases the rate of discarding as the quantity of queued data increases above the preset threshold, discarding all data traffic when the queue is full.

Abstract: An apparatus comprising an input capable of receiving a bandwidth optimized transport stream is provided. The bandwidth optimized transport stream can be produced by receiving a transport stream of variably compressed program data bearing transport packets and one or more null transport packets. One or more of the null transport packets is selectively replaced with another to-be-remultiplexed non-null data bearing transport packet. Independently of determining an amount of information carried by a program data bearing transport packets from time to time in the received transport stream, at least one selected program bearing transport packet is scheduled for output in an output remultiplexed bitstream.

Abstract: A network interface that processes data packets transmitted on a network is provided. The network interface includes a first data path, a second data path, a header processor, a classifier unit, and a plurality of packet processors. The first data path unit inputs downstream data packets transmitted downstream on the network, and the second data path unit inputs upstream data packets transmitted upstream on the network. The header processor inputs data packet headers of the downstream and upstream data packets from the first and second data path units and classifies the downstream and upstream data packets by comparing the headers with predetermined rules. The classifier unit also inputs the data packet headers from the first and second data path units and evaluates the headers determine flows corresponding to the downstream and upstream data packets.

Abstract: The object of the invention is a method for reserving transmission capacity required by the acknowledgement and/or response messages (33) in a bi-directional transmission system, where a message (16) is transmitted from a first unit (12) to a second unit (13), the second unit (13) receives the message (16) transmitted by the first unit (12), and the second unit (13) transmits an acknowledgement and/or response message (33) as a response to the received message (16) so that the reservation of the transmission capacity required by the acknowledgement and/or response message (33) is made substantially in connection with the transmission of the message (16) transmitted from the first unit (12) to the second unit (13).

Abstract: Congestion across links in a network, such as the Internet, is reduced by diverting traffic from the congested link to alternative, shortest paths by adjusting splitting factors associated with the congested and alternative links. The alternative shortest paths comprise equal cost paths. Alternatively, adjustments occur after the creation of additional equal cost paths/shortest paths if none are initially available within the network. Unique programs control the adjustment of the splitting factors and the creation of the additional shortest paths. The programs make use of both existing, real networks and constructed, virtual networks in conjunction with novel traffic flow relationships to divert traffic from a congested link without causing further congestion within the network. Another unique program deletes shortest paths once used to accept traffic diverted from a congested link when traffic in the network decreases.

Abstract: A network including a host device and a plurality of transceiver beacons for communicating data from terminal devices interacting with the beacons, to the host. The beacons include identification codes used by the host for establishing wireless communication links either between a beacon and the host, or between two or more beacons. A routing mechanism is included in the beacons for selecting a most favorable transmission path among available paths for communicating data to the host.

Abstract: A data communication apparatus includes a communication section that performs a pre-communication protocol with a destination terminal and transmits data to a destination terminal. A memory stores data and communication parameters corresponding to each destination terminal, the communication parameters being utilized to perform communication with the destination terminal. When destination terminal data is stored in the memory, a controller reads the communication parameters corresponding to the destination terminal from the memory, performs the pre-communication protocol with the destination terminal, using the read communication parameters, and omits at least a communication protocol for line probing.

Abstract: The invention replicates a packet requiring high availability and transmits it from two or more ports of a switch, for example a wiring closet Layer 2 switch. The parent packet carries a unique sequence number. The copies of the packet each carry the parent packet's unique sequence number. Each copy of the packet then travels on separate pathways through routers (Layer 3 network devices). The pathways are maintained separate by assigning high costs in a LSP routing sense to links connecting the two paths, and by assigning low costs to links along the desired paths. The two identical packets converge on the destination station. The destination station accepts the first packet with a particular sequence number, and discards any later packets with the same sequence number. In the event that a link in one path has a catastrophic failure, then the packet travelling along the other path reaches the destination station and service remains operative without interruption.

Abstract: The present invention provides a method and audio-video conferencing system for efficiently utilizing a Home Network system with a controller and having home audio and video devices coupled by IEEE 1394 standard compliant connections in one of: point-to-point and multipoint arrangement.

Abstract: A filter cell, method of deriving an echo component and an echo canceling system, bit pump and transceiver employing the same. In one embodiment, the filter cell includes a first summing node that receives a first input based on a signal sample that contains an echo component of an echo. The filter cell also includes a second summing node that receives a second input based on the signal sample. The filter cell still further includes a multiplier that employs outputs from the first and second summing nodes and a scaling factor to derive first and second outputs containing a remnant of the echo component.

Abstract: A received RF signal can include data information intended for transmission over a wireless communication link. The data information of the signal can be processed at a node to produce overhead bits supporting a serial transmission of the data information over a communication medium to another node. For example, the data information of the received signal and overhead bits can be combined or framed according to a serial transport protocol for transmission over the communication medium. This technique of mapping or framing the data information into a serial transport protocol is used to more efficiently transmit the data over the communication medium to a target receiver, where the original RF signal can be reconstructed.

Abstract: Information packets are routed through a distributed routing network by determining a forwarding equivalency class (FEC) for each subscriber unit accessing the network. The FEC to which each subscriber unit belongs is based on the point at which the subscriber unit accesses the network. The forwarding equivalency class for each subscriber unit is updated if the subscriber unit accesses the network at a different point. Information packets are routed from a distribution point by determining the next point connected to the distribution point based on the forwarding equivalency class for the destination subscriber unit specified in the packet.

Abstract: A method and apparatus of providing a public network service when a call management device is in a down state in a private wireless network is disclosed. The present invention provides the public network service when a call management device is in a down state in wire and wireless composite communication system serving through wire terminal and a wireless terminal by connecting the wireless network to an extended network linked to the public network. The method of providing a public network service having the steps of periodically checking, at the base station controller, a state of the call management device, and performing the wireless public network service when the call management device is in a down state.

Abstract: A mobile communication system includes a line control station, and a plurality of base stations belonging to a plurality of clusters so that each of the clusters includes a plurality of base stations. Each of the clusters includes a cluster control station which is connected to the line control station via a line and controls the base stations within the cluster to which the cluster control station belongs. In addition, each of the base stations within one cluster is connected to other base stations within the one cluster and/or the cluster control station within the one cluster via lines, so that each of the base stations within the one cluster is directly or indirectly connected to the cluster control station within the one cluster.

Abstract: A spread spectrum system having an assignor, a spread-spectrum processor and a transmitter. The assignor assigns each arriving information signal to a message-code signal. Each message-code signal is different then other message-code signals. The spread-spectrum processor generates a pilot code signal and processes the information signals with the message-code signals to generate spread-spectrum process-message signals synchronized to the pilot-code signal. A transmitter combines the spread-spectrum process-message signals and the pilot-code signal to generate a CDM signal. The transmitter modulates the CDM signal with a carrier signal for transmission over the communications channel.

Abstract: A method and apparatus provides for efficient use of communication resources in a CDMA communication system (100) by selecting, at a time prior to a first time period (401), a first mobile station to receive transmission during the first time period (401) on a downlink shared channel, and selecting, at a time prior to the first time period (401), a second mobile station to receive transmission during a second time period (402) on the downlink shared channel. Transmission power level of a downlink shared control channel is determined for transmission to the second mobile station during an overlapping time period (403) with the first time period (401), and the transmission power level of the downlink shared channel for transmission during the first time period (401) is determined based on at least the determined transmission power level of the downlink shared control channel during the overlapping time period (403).

Abstract: A method of broadcasting commercial FM services in a digital format in at least one bitstream comprises time-division multiplexing the bitstream(s) into one or more channels comprising a data frame, and frequency modulating the data frames around a single carrier frequency into a commercial FM broadcast signal. The modulation may comprise GMSK or 8-PSK, and multiple data frame types may be interleaved. The signal is transmitted on a commercial FM broadcast station such that substantially the entire spectrum of the transmission comprises the digital data frames. The bit rate(s) of the digital bitstream(s) may be monitored, and the bitstream(s) may be reallocated to channels in the data frames based on changes in the bit rate(s). Analog and digital formats may be broadcast simultaneously on non-adjacent commercial FM broadcast carrier channels. A receiver is operative to extract and decode content from a digital format FM broadcast signal.

Abstract: A data communication system, which sends or receives data to or from an application server using the same protocol via a transmission line as one of a wire communication network, a wireless communication network, and both a wire communication network and a wireless communication network, comprises a table 14 containing therein a relation among a service identifier of the application server, a destination address, a communication network type, and a processing time of the application server; and a retransmission timer setting unit 16 which references the table to obtain the processing time of the application server based on the service identifier, destination address, and communication network type during transmission or reception of data to or from the application server and sets the time as a retransmission time.

Abstract: A channel assigning device and method in a CDMA communication system is described. According to one aspect of the present invention, in a channel assigning method for a base station, the base station establishes a first dedicated channel and communicates with a mobile station on the established dedicated channel. Then, the base station determines the type of a second dedicated channel and channel spreading code information upon request for additional assignment of a second dedicated channel while in the conversation state, assigns the second dedicated channel, and generates a channel assignment message including the determined channel assignment mode and channel spreading code information to assign the second dedicated control channel. The base station transmits the channel assignment message to the mobile station on the first dedicated channel.

Abstract: A common power control channel transmission device for a base station in a CDMA communication system is provided having a selector for receiving power control commands to be transmitted to multiple subscribers and multiplexing the received power control commands; and a spreading modulator for spreading an output of the selector by multiplying the output of the selector by a spreading sequence. The common power control channel transmission device can be used to control power of a reverse link common channel. For the power control of the reverse link common channel, the base station receives a signal from a mobile station via the reverse link common channel, and transmits to the mobile station a power control command for controlling a transmission power of the reverse link common channel according to a measured strength of the received signal.

Abstract: A system and method for processing signals from at least two sources, using a receiver having a timer and a local code sequence, the method comprising, providing at least one signal channel divided into a plurality of sequential time slots processing said signal from a first of said two sources in a first time slot of the plurality of time slots to provide a first time slot signal, processing said signal from a second of said two sources in a second time slot of the plurality of time slots to provide a second time slot signal, processing said signal from said first of said two sources in a third time slot of the plurality of time slots to provide a third time slot signal, said first, second and third time slots occurring in sequential order, comparing said local code sequence to said signals in said first and third time slots by incrementing the local code sequence during the interval between said first and third time slots.

Abstract: A system for efficiently and reliably communicating over a high-speed asymmetric communications link. The system includes a first mechanism for connecting a first device to a second device via a channel. A second mechanism delivers data packets over the channel from the first device to the second device. Each packet is associated with a window of packets. A third mechanism selectively employs the second mechanism to re-send data packets not received by the second device after each window of packets. The window of packets is sized in accordance with the bandwidth of the communications link between the first device and the second device, and the round trip delay time. In a specific embodiment, the first mechanism (includes Transmission Control Protocol/Internet Protocol (TCP/IP) functionality on the first device and the second device for establishing a first TCP/IP link from the second device to the first device.

Abstract: The invention relates to a method of identifying a protocol data unit in a network layer of an air interface in a cellular radio network, to a cellular radio network and to a protocol data unit. A network layer usually includes connection management, mobility management and radio resources management sublayers. In the invention, the radio resources management sublayer is replaced by a radio network sublayer. A protocol data unit header includes a protocol discriminator. Some of the protocol discriminator values are allocated to the identification of protocol data units in the connection management sublayer and the mobility management sublayer. According tot the invention, at least one unreserved value of the protocol discriminator is used for identifying protocol data units in the radio network sublayer.

Abstract: In a telephone network, an intelligent peripheral (IP) provides a variety of auxiliary call processing functions, such as announcement playback and digit collection. In response to each call, the IP queries a service control point (SCP) over a data network, for instructions as to processing of the call. The IP runs software to select one SCP for control of each call, from a number of SCPs on the data network, and obtain the requisite instructions for the call from the identified SCP. For each call, the IP software identifies the telephone number of the subscriber and uses the NPA-NXX and D digits from that number to access a first mapping table and obtain a CLLI code identifying an SCP. Using the CLLI code from the first table, the IP software accesses a second mapping table to obtain the CLLI code for the mate to the identified SCP. Using the two CLLI codes, the IP also goes through the second table to obtain all of the Internet Protocol addresses for the two SCPs.

Abstract: A telephone network is provided with a service node SN (50) having an interface to the Internet. The SN (50) has a voice service browser (51) which it can use to access resources on the Internet, these resources preferably being held on WWW servers (52). A user of the telephone network places his own service logic programs, in the form of applets 55, on his WWW home page (53) together with content items such announcements and messages; these content items may be embedded in the applets (55) or held in separate files. When the SN (50) receives a service request to supply a service to a user identified as having his own service logic programs and content items available on the WWW, the voice service browser (51) reaches out over the WWW to retrieve the relevant service applet (55) and any associated content items. The voice service browser (51) then executes the applet (55) to provide the desired service including the delivery of content items through a text-to-voice converter or the like.

Abstract: A host system is provided with one or more host-fabric adapters installed therein for connecting to a switched fabric of a data network. The host-fabric adapter comprises a micro-controller subsystem configured to establish connections and support data transfers via the switched fabric, and a serial interface which provides an interface with the switched fabric. The micro-controller subsystem includes a Micro-Engine (ME) which executes a ME instruction to send source and destination addresses during a control cycle, and interface logic blocks which supply addressed data from designated sources to the Micro-Engine (ME) at the same time for execution of the ME instruction during a data cycle subsequent to the control cycle.

Abstract: A method for using network address translation in switches and routers to define a virtual host as the source of a multicast channel within a single-source multicast model and to translate packet addresses from different multicast sources so that the packets appear to be originating from the virtual host. Address-translated packets are thus forwarded through a single-source multicast channel and received by the subscribing host(s)/clients as though the packets came from a single “virtual” source. This methodology can be used to map two or more sources simultaneously onto the same multicast channel. Such a mapping is useful, for example, to present multiple views of a sporting event video broadcast, provide advertisement insertion capability, or to support transparent fail-over to a backup video source in a critical multicast application. Subscribing client hosts in the multicast reception group simply subscribe to the single virtual host as the source of a multicast channel.

Abstract: An ATM transmission system is adapted for the simultaneous transmission (i.e. multicasting) of IP data packets to a plurality of system users, using ATM as a carrier network, and includes an IP/ATM network including clusters of Logical IP Systems (LISs), a multicast address resolution server (MARS) for each cluster, and a multicast router (MCR) for each cluster. The clusters are interconnected through the MCRs which form an inter-cluster backbone for the IP/ATM network. Each cluster includes an integral number of ATM hosts and LISs, the size of a cluster is dependent on physical and administrative constraints, and each LIS, within a cluster, is adapted to support a number of ATM hosts. Multicasting of IP data packets within a cluster utilizes a MARS protocol, and multicasting between clusters utilizes an inter-cluster multicasting protocol (ILMP). All ATM hosts within a cluster, even if supported by different LISs, are adapted to be configured with an address of the same MARS.

Abstract: A low-speed subscriber extension type system interfaces with a switch link through a system backboard, receives a cell transmitted from the switch link, then multiplexes/demultiplexes the received cell through a UTOPIA interface after a switch link and ATM layer processing. A low-speed subscriber physical layer board transmits data, which is physical layer-processed in the low-speed subscriber board, to a low-speed subscriber, and serializes a cell transmitted from the low-speed subscriber board into a clock and data before transmission. Each low-speed extension board exchanges a cell with the low-speed multiplexing/demultiplexing board through a low-speed bus, performs physical layer processing on the cell of the corresponding board, and transmits a received cell to the corresponding subscriber through the low-speed extension physical layer board.

Abstract: A memory vacancy management apparatus for managing vacant addresses of a memory which is capable of storing various information, includes a vacant address management table having a number of addresses identical to a number of addresses of the memory, and storing vacancy information indicating whether or not the addresses of the memory are vacant. The vacancy information with respect to an address of the memory having an arbitrary address value is stored at an address of the vacant address management table having the same arbitrary address value.

Abstract: A wireless network access system and method that provides a multiplicity of access point devices, each being capable of relaying information. The upstream network access may include an omni-directional antenna for downstream communications. The wireless network is provided as a tree structure wherein each access point feeds back to a higher access point of the multiplicity of access point devices. The described system does not employ routers, and thereby speeds processing time and reduces network latency and costs associated with a mesh network employing routers. A multiplicity of customer premise wireless network devices are provided with a wireless modem for communication from the customer premise limited to a path all the way back to a main gateway upstream to the wired side of the network where the gateway provides a T3 or other high speed Internet connection.

Abstract: A contention priority control circuit which receives data of two priority classes from a plurality of input ports, and arbitrates contention between output requests for outputting these data to a bus on the basis of the priority classes and priorities determined for the respective input ports includes a plurality of arbiters which are arranged at a plurality of input ports for receiving data of the two priority classes, and receive data output requests for each of the two priority classes, a forward high-priority ring for connecting the plurality of arbiters in a forward direction, a forward low-priority ring for connecting the plurality of arbiters in the forward direction, and a backward high-priority ring for connecting the plurality of arbiters in a backward direction opposite to the forward direction.

Abstract: A pipelined multiple issue architecture for a link layer or protocol layer packet switch, which processes packets independently and asynchronously, but reorders them into their original order, thus preserving the original incoming packet order. Each stage of the pipeline waits for the immediately previous stage to complete, thus causing the packet switch to be self-throttling and thus allowing differing protocols and features to use the same architecture, even if possibly requiring differing processing times. The multiple issue pipeline is scaleable to greater parallel issue of packets, and tunable to differing switch engine architectures, differing interface speeds and widths, and differing clock rates and buffer sizes.

Abstract: A variable communication systems comprising a plurality of transceivers and a control circuit connected to the transceivers to configure the transceivers to operate in a bi-directional mode and a uni-directional mode at different times using different transfer methods to transfer data.

Abstract: A structure and process are provided for using a single wire or data bus to detect collisions between two communication nodes connected by the single wire by sensing current changes in the wire, where large current changes indicate a collision. When a second node wants to obtain control of the wire on which a first node is transmitting data, the second node transmits a special data packet to ensure a collision and cause a large current to flow on the wire. Once a large current is detected in the wire to indicate a bit difference or collision, the first node stops transmitting and waits until it receives a synchronization bit pattern, which will indicate that the special data packet transmitted by the second node has ended. The two nodes are now synchronized, such that the second node has control of the wire and can begin transmission of a data packet. In order to indicate a collision, the large current flow must remain high after a specified time interval, such as a clock cycle.

Abstract: The adapter/coupler links at least one legacy signal to a wideband network having a defined protocol. The adapter/coupler may be used with a wideband network having a signaling speed of 90 megabits per second, or greater. The adapter/coupler includes a signal conversion/conditioning element for receiving at least one legacy signal and providing a conditioned digital signal which is compatible to the defined protocol of the wideband network. A low latency controller element receives the conditioned digital signal and provides data/control signals. A link/physical layer element receives the data/control signals and transforms them to appropriate signaling mechanisms of a defined physical layer standard in accordance with the defined protocol. The transformed signals are outputted to the wideband network. The latency from the reception of the conditioned digital signal from the signal conversion/conditioning element to the output of the transformed signals to the wideband network is less than 200 microseconds.

Abstract: In a distributed switch architecture, each incoming signal is sliced into a plurality of sub-signals. A checksum function is applied to subsets of data in each sub-signal to generate and add a checkbit to the sub-signal for each subset of data. Two copies of the augmented sub-signal are routed in parallel through redundant portions of the distributed switch fabric. Only one of the resulting routed sub-signals is selected for use in generating the corresponding outgoing signal, which is generated by combining data from selected routed sub-signals corresponding to all of the original sub-signals. Checksum analysis is performed on the two routed sub-signals to determine if a fault has occurred. If a fault is detected in the routed sub-signal currently being selected for use in generating the outgoing signal, the selection is changed so that the other routed sub-signal is used.

Abstract: Various methods for ensuring compatibility between devices utilizing the IEEE 1394-1995 serial bus standard and new implementations of the standard are disclosed. Methods are disclosed which a allow border nodes to speed filter a Legacy cloud. Methods are disclosed which allow a BOSS node to speed filter a Legacy cloud. A method for ensuring compatibility is disclosed which comprises the acts of determining whether the B PHY desires to communicate at a speed on a bus having a peer device not capable of communicating at the speed; and speed filtering the peer device if the B PHY determines that the peer device cannot communicate at the speed. Various data packets and methods for transmitting data packets are also disclosed to satisfy the needs discussed herein.

Abstract: A circuit for detecting a serial signal comprises a first circuit (400) coupled to receive the serial signal (200) during a predetermined plurality of time periods of substantially equal duration. The first circuit is coupled to receive a first code (414). The first circuit is arranged to compare a part of the serial signal corresponding to each time period of the plurality of time periods to the first code, thereby producing a match signal. The first circuit accumulates the match signal from each of the each time period of the plurality of time periods.

Abstract: The present invention is directed to a telecommunications system and access panel for providing direct metallic access to a telecommunications carrier's signal pairs by a competitor while providing isolation between the telecommunications POTS service and the competitor's digital line service. The isolation is provided by placing DC blocking capacitors in the access panel. In another embodiment, direct metallic access is achieved by placing the access panel as an intermediate distribution frame member.

Abstract: A transport demultiplexor system and queue remultiplexing methodology includes: a packet buffer for receiving data packets belonging to an input transport stream, each packet having a corresponding identifier identifying a program to which the packet belongs; a data unloader device for pulling successive packets from the packet buffer for storage in a memory storage device, and writing the pulled packets into contiguous address locations in the memory; and, a remultiplexor mechanism for generating an address offset associated with a next data packet pulled from the packet buffer to be stored in memory and writing it to a new memory location that is offset from a memory location assigned to a previously pulled packet, the offset defining a memory gap in the memory storage device capable of being filled new data content.

Abstract: Synchronous Optical NETwork (SONET) traffic is sent across a packet network. A SONET transmission is decoded into a data structure. The data structure is then converted into one or more packets and sent across the packet network.

Abstract: A system and method for implementing a next generation laser-like light source with Free Electron Lasers (FELs) are provided whereby the construction of a Free Electron Laser (FEL) is customized through the use of individual modules having specified characteristics. Such individual modules include conventional lasers, electron guns, linear accelerators, magnetic bunch compressors and permanent magnet, hybrid, and electromagnetic, undulators or a combination of these undulators. These individual modules are arranged to exploit the occurring fundamental and nonlinear harmonics generated in each SP HG FEL to be used themselves as a light source, or alternatively to be a coherent seed for another module, such as, in high-gain harmonic generation (HGHG). An efficient method for producing shorter wavelengths of a synchrotron light source is provided. A three step process including imprinting, upconverting or wavelength shifting and reinforcing or strengthening of the electron beam microbunching is provided.

Abstract: A double cladding fiber includes an inner core doped with active species, an inner cladding disposed adjacent said inner core for receiving pumping energy, minimizing local modes in said inner cladding, and transferring said pumping energy to the core. An outer cladding is disposed adjacent the inner cladding. The cross section of said inner cladding has a polygon-like shape with its boundary being a plurality of well-defined arcs, each of the arcs having substantially different arc center for delivering energy with maximum efficiency to the inner core meeting the limitation of: (1−L/r1)(1−L/r2)<0, or (1−L/r1)(1−L/r2)>1; where r1 and r2 is the arc radius of the inner cladding surfaces that are opposite to each other (mirror pair), with the radius of a concave mirror being positive and that of a convex mirror being negative, L is the distance between two mirrors.

Abstract: Accurate and efficient synchronization of two pulsed radiation sources (e.g. iwo mode locked lasers) is accomplished in stages. Rough synchronization is accomplished by synchronizing (for example) the fundamental repetition rate of the two lasers. Fine synchronization is accomplished by synchronizing high harmonics of the two lasers. More accurate synchronization may be accomplished by adding more stages, by utilizing light out of a nonlinear laser in which the two beams are crossed, or by utilizing heterodyne beats of the two laser beams. A dc offset signal may added to the control signal generated by the synchronization stages.

Abstract: A pulsed laser system includes a laser pump, a laser rod, a reflector interposed between the laser pump and the laser rod, through which energy from the laser pump enters the laser rod, an output reflector through which energy is emitted from the laser rod, a switch interposed between the laser rod and the output reflector, and a control device. The switch, when closed, causes energy to be stored in the laser rod and, when opened, allows energy to be emitted from the laser rod during an emission period. The control device allows a primary laser pulse emitted from the laser rod during the emission period to impinge on a workpiece and blocks from the workpiece secondary laser emission occurring during the emission period after emission of the primary pulse. The pulsed laser system is operated over a range of repetition rates, so as to cause laser energy to be emitted during a plurality of emission periods at each repetition rate.

Abstract: A method of fabricating a semiconductor laser device includes the steps of forming semiconductor layers composed of a first conductive type cladding layer, an active layer, and a second conductive type cladding layer on a substrate, and peeling a device formation region of the semiconductor layers from the substrate and simultaneously forming a resonance mirror on an end portion of the device formation region by irradiating the device formation region with energy beams traveling from the back surface side of the substrate. With this configuration, it is possible to peel a device from a substrate and also form a flat resonance mirror with less damage of crystal by laser abrasion, and further to easily form a high quality resonance mirror without increasing the number of fabrication steps.