Abstract: A method is provided for minimizing the peak power level in a combination of orthogonal frequency division multiplexed (OFDM) tones. The method is particularly effective when the information to be communicated is digital data consisting of long patterns of “1”s or “0”s. The digital data of the message is combined with a scrambling vector before the data is modulated. The randomization of data patterns, in turn, leads to a more random combination of OFDM tone amplitude being transmitted. The message is recovered at the receiver by removing the scrambling vector. A table of scrambling vectors is maintained at the transmitters and receivers. The table pointer to select the scrambling vector is selected in response to the position of the message in the communication structure. An OFDM communication system using the above-described method is also provided.

Abstract: The link layer (68, 64) of the sending end of a wireless link (66) is enhanced (10, 74) by providing a mechanism for discriminating (36, 38; 79, 82) between special, critical or otherwise important packets from among a plurality of packets send over the wireless link. Special link layer treatment (42; 89) is accorded to such special, critical or otherwise important packets, while the remaining packets are subjected to normal link layer treatment (44; 86) before transmission over the wireless link.

Abstract: The present invention permits quality-of-service routing without using any flow pinning or per-flow state mechanisms. In accordance with the present invention, load insensitive routing techniques are utilized for QoS traffic while load sensitive routing techniques are utilized for best effort traffic. In accordance with a preferred embodiment of the present invention, conventional static shortest path routing is utilized for flows that require QoS guarantees while known QoS routing techniques are utilized for best effort flows. Unlike the prior art, a single queue per class per link can be utilized at a network node. The present invention has numerous advantages over the prior art including reduced protocol overhead, lower cost, and reduced route instability.

Abstract: A mechanism for recovering data associated with lost packets, suitable for use in a VoIP network. The telecommunications network is preferably a packet switched network having IP telephony gateways serving as interfaces between a telephone device and the IP network. The IP telephony gateway receives a conversation signal from the telephone device, and implements an improved forward error correction method. The method includes generating payload information defined by at least two packet sequences from the same audio information, and transmitting those two packet sequences on the IP network for receipt by a remote network device. The packet sequences are transmitted using RTP with two independent data streams or, alternatively, using a single data stream. The first and second data streams are data packet streams each defining a sequence of data packets. The first data stream is preferably formed using a G.711 vocoder, and the second data stream is preferably formed using a G.723.1 vocoder.

Abstract: A method and apparatus for reducing voice latency in a voice-over-data wireless communication system. In a transmitter, data frames are created from audio information by a vocoder and stored in a queue. Prior to storage, some of the data frames are eliminated, or dropped, and are not stored in the queue. In a receiver, data frames are generated from received signals and stored in a queue. Prior to storage in the receiver queue, some of the data frames are dropped. Data frames are dropped either at a single fixed rate, a dual fixed rate, or a variable rate, generally depending on a communication channel latency. By dropping data frames at the transmitter, the receiver, or both, voice latency due to data frame retransmissions is reduced.

Abstract: Each of gateways GW1, GW2 includes packet-switched network control portions 32, 33 connected to packet-switched networks, a circuit switched network control portion 35 connected to a circuit switched network, and a call control portion 31 for controlling a communication call together with the packet-switched network control portions and the circuit switched network control portion and for monitoring the traffic of the packet-switched network. The packet-switched network control portion includes plural circuit connection portions 37, 38 which can be connected to plural circuits, plural CODECs 34 having different compression ratios for enabling real-time type data transmission, and a storage data processing portion 32 for enabling store-and-forward type data transmission.

Abstract: An inexpensive and flexible method and apparatus for inter-working in circuit, packet and circuit packet networks between one or more access protocols and one or more destination protocols. By consolidating the inter-working logic in an Abstracted Common Call Control Inter-working Function (ACCCIF) that operates on abstracted signals and events, configuration and maintenance are simplified. At the same time, extending the invention by adding, updating or deleting protocols may be achieved quickly and consistently while the need to buy additional equipment in order to extend services is minimized. A preferred embodiment utilizes protocol engines and is implemented as a finite state machine.

Abstract: A digital subscriber line access network comprises a remote Ethernet device disposed in a serving area interface. The remote Ethernet device serves as an Ethernet bridge for a neighborhood service area. The remote Ethernet device communicates with a plurality of customer premises modems in the neighborhood service area using an Internet Protocol over an Ethernet standard with a digital subscriber line physical layer. An Ethernet switch disposed at a central office communicates with the remote Ethernet device via a fiber optic medium using an Internet Protocol over a second Ethernet standard. The Ethernet switch provides a packet data core network termination.

Abstract: An Internet controlled telephony system employing a host services processor connected to a subscriber via the Internet and further connected to the public switched telephone system (PSTN). The subscriber employs a web interface to populate a database with preference data which is used by the host services processor to handle incoming calls and establish outgoing telephone connections in accordance with the preference data provided by the subscriber. Incoming calls to a telephone number assigned to the subscriber may be automatically forwarded to any telephone number specified by the preference data.

Abstract: A telephone to digital data network interface 118 and method for its operation are disclosed. Interface 118 provides a connection point 52 and a standard line interface 50 for a POTS phone. Audio quality selector 86 interprets signaling received from a POTS phone (e.g., hookswitch signaling, DTMF signaling, or voice recognition commands) to select between multiple audio paths within interface 118. A first audio path includes the telephone line interface 50 and provides telephone-grade audio. Preferably, a second audio path includes a wideband audio output device (speaker 114) and a wideband audio input device (microphone 116). Audio quality selector 86 selects one of these paths using switches 106 and 108. It also communicates with digital audio processor 90, which preferably contains both a telephone-grade and a wideband audio codec and is capable of call-in-progress reconfiguration between the two.

Abstract: A digital switching system capable of changing switching capacity without any recourse of increasing or decreasing the quantities of line terminals or cross-point switches. The digital switching system comprises line terminals which send and receive data as serial data to and from the user, a switching arrangement which switches, based on destination information, the parallel data converted from the serial data, and data converters capable of converting between the serial data and the parallel data at a specified conversion ratio. The serial/parallel converter circuit of a serial/parallel converter in a digital switching system comprises a 1:4 transceiver, four variable converters, and 16 selector circuits The 1:4 transceiver converts serial data into 4-bit wide parallel data and sends the parallel data to the variable converters. If mode selection information specifies a conversion ratio of 1:4, only a tristate buffer is enabled and 4-bit wide parallel data is output.

Abstract: A control interface unit (1) for the realization of a simultaneous controlling of at least two logical units is provided, as well as an appertaining method, in which a control field evaluation unit (2) evaluates a transmitted control field (SF) and produces a control value (SF′). Depending on the control value (SF′), an address field conversion unit (3) converts a transmitted address field (AF) into a relevant address (ASIC-Adr), by which a data field selection unit (4) selects, dependent on the control value (SF′), a data field (DF1, DF2) that fits the address. In this way, one obtains, with the use of a common control interface, a simple and economical simultaneous controlling of at least two logical units.

Abstract: In another embodiment, an ASIC device includes a first RAM that stores a code for each of multiple first time slots. Each code is combined with corresponding data from a first bus to specify a previously stored operation. A second RAM receives the combined data and code for each first time slot and applies the specified operation for each first time slot to generate modified data for each first time slot. A third RAM stores information specifying a second time slot to correspond to each first time slot and communicates the information for each second time slot as an address. A fourth RAM stores the modified data for a previous frame and the modified data for a current frame, locates the modified data for each first time slot of the previous frame according to the address, and communicates the modified data for each time slot of the previous frame to a second bus in the corresponding second time slot while the modified data for the current frame is being stored.

Abstract: A group switching apparatus for multi-channel data is disclosed. It includes a speech memory to temporarily store a time slot to be switched, and a connection memory (CM) to store group connection information. Also, it includes a processor matching unit to interface group connection information provided from an upper processor to the CM and a counter to count a system clock signal and output a read address for the CM. Additionally, an offset generating unit receives group connection information outputted from the CM and generates a first offset value according to a signal representing an ‘ON’ state of group connection, and an adder adds the output of the counter and the output of the offset generating unit and outputting the added value as a read address for the SM.

Abstract: The present invention is directed to an apparatus and a method of controlling a stacked switching system. The stacked switching system according to the present invention has a plurality of switches connected to each other through a network backplane. One of the switches in the stacked system is designated as the master unit, whereas the remaining switches are designated as the slave units. The present invention discloses two topology designs for assigning the master duties among the plurality of switches. The first topology design is termed as a fixed topology and the second topology design is termed as a dynamic topology. Both of these two topology designs assign the master control to the switch having the highest priority index. This master duties assignment is performed whenever there is a deletion or addition of switching unit to the system. For the fixed topology design, the master control assignment can only be performed after rebooting the system.

Abstract: The present invention presents methods and apparatus supporting traffic engineering in a connectionless protocol network constituted by a core of plain routers, without dependencies on the underlying link protocol. The IP is used as an example of a connectionless protocol. It also enables a network operator to perform traffic engineering on a core network of plain routers supporting any connectionless protocol.

Abstract: Efficient switched network multicasting techniques are provided. Incoming multicast packets are processed by a central forwarding engine (CFE) in a network switch to generate forwarding indices used to make forwarding decisions for the packets based upon whether the packets are special multicast control packets or data packets. Forwarding of the special multicast control packets is determined by the switch's network management processor (NMP), while data packets are forwarded based upon conventional bridge forwarding techniques.

Abstract: A routing table for use with a router in a world-wide network, includes an existing routing table with a multicast-destination (MD) column.

Abstract: A packet-based telecommunication system (100) is disclosed, comprising a first media gateway (124) having a first CODEC structure (130), a second media gateway (126) having a dual function CODEC structure (132), wherein the dual function CODEC structure is adapted to provide tandem free operation between itself and the first CODEC structure, and wherein the dual function CODEC comprises a first element (134) adapted to negotiate tandem free operation, and a second element (136) communicatively coupled to the first element and adapted to selectively convert data coding responsive to the first element.

Abstract: A system and method for facilitating the routing of small information packages between nodes in a network. In particular, the system and method of the present invention utilize a routing table at each node of the network. The routing table for each node contains a list of the nodes, ordered the same in each table, and an indexing value is utilized to refer to particular node values. Internodal linkage information is also stored in the routing table along with an alternative link should the primary link fail. The addition/deletion of nodes and the failure of any link is handled by an update function.

Abstract: Methods systems and computer program products are provided for hashing address values that exhibit banding in a plurality of regions of an address space defined by at least two segments of the address values, by performing at least one of a translation and a rotation of the at least two segments to thereby map the at least two segments from the plurality of regions to one of the plurality of regions.

Abstract: A destination local area network (LAN) and a local LAN are coupled by an FR-ATM Service Interworking (SIW)-based wide area network (WAN). In order to identify a connection between the destination LAN and the local LAN, an end-to-end LAN-WAN-LAN connection components template is created, which contains a number of fields which are populated during the course of identifying the connection. FR and ATM interfaces are identified on each router. The network addresses conform to Internet Protocol (IP) and are part of the same subnet. The IP address, IP subnet mask, city, state, DLCI value retrieved from the FR interface, and the VPI/VCI values retrieved from the ATM interface are stored to create a list describing the physical and logical characteristics of the FR and ATM interfaces. A pair of network addresses is identified using the IP address in conjunction with the subnet mask stored on either the FR or ATM interface in the list. The DLCI value associated with each of the network IP addresses is identified.

Abstract: An ATM connection (45) and call connection equipment 22 can be dynamically allocated between exchanges (20, 30). The connection is setup and released by a master switch (20) on one side of the connection. The slave 30 is controlled using standard signaling protocols and the physical connections (45) between the interworking units (40, 50) use circuit-emulation according to AAL1. The master (20) controls the ATM connection (45) with standard signaling and the slave (30) with normal trunk signaling. The ATM connection 45 and connection 26 can be setup between the nodes (40, 50) when needed based on the traffic needs of the network (10).

Abstract: A method of transferring data in a connection-type network in which nodes are connected via communication lines and terminals are connected to the nodes includes the steps of sending a request from a first one of the terminals to a second one of the terminals via a connection established on a first communication line, the request requesting transfer of data from the second one of the terminals to the first one of the terminals via a second communication line, establishing a connection on the second communication line between a first one of the nodes having the first one of the terminals attached thereto and a second one of the nodes having the second one of the terminals attached thereto, and transferring all or part of the data via the connection on the second communication line, wherein the second communication line is established to be in existence for a predetermined duration of time or for a time period during which all or part of the data is transferred.

Abstract: A system and method for connecting a call in a gateway system comprises a signaling processor for processing call signaling to determine connections for the user communications. A gateway matrix accepts control messages form the signaling processor and accepts user communications from switching systems. In response to the control message, the gateway matrix connects the user communications to the designated connection.

Abstract: A method for deadline based scheduling for asynchronous transfer mode adaptation layer, type 2, messages, in accordance with the present invention, includes calculating, for a list of channels, a last possible transmit time for messages on each of the channels in accordance with system criteria. The list of channels is prioritized in an ordered list based on a last possible transmit time for the messages for each of the channels. The messages for the channels are transmitted in accordance with the ordered list. Also disclosed is a method for requesting for quality of service.

Abstract: A DMA system includes a plurality of transmit-receive pairs (102, 104) for communicating on a bus. A DMA controller (108) supervises bus handling. The DMA controller (108) includes a priority controller (114), a bus sniffer (112), and a context machine (116). The bus sniffer (112) and context machine (116) identify block transfers as frame or cell transfers and supervise interleaving. The priority controller (114) resolves the priority of each of the constituent transfers of the frame or cell block transfers using a matrix of priority tokens.

Abstract: A method and system for communicating traffic on an emulated subnetwork of a telecommunications ring having a plurality of nodes interconnected by a transmission media includes obtaining traffic at a node on the telecommunications ring. The traffic is segmented into a plurality of discrete segments. A set of broadcast cells is generated by adding an address header to each segment. The address header identifies a virtual channel dedicated to the node on the subnetwork in the telecommunications ring. The set of broadcast cells are transmitted in the virtual channel of the subnetwork and within a frame of the telecommunications ring. At each remaining node on the telecommunications ring, in response to receiving the set of broadcast cells in the virtual channel, both retransmitting and processing the broadcast cells.

Abstract: A stackable multi-port communication device for a packet-based data communication system, having a multiplicity of physical ports for the reception and dispatch of data in the form of packets, includes switch logic for selecting for a packet at least one destination selected from a multiplicity of ports which include a logical port common to a specified group of said physical ports. A cascade trunk logic, coupled to the switch logic, is used for determining, for the dispatch of a packet directed to said logical port, a selected port of said group of said physical ports; and a remote monitoring logic is used for forwarding a copy of the packet.

Abstract: The invention is a system and method of initiating a communication which is transmitted by a packet data network (14), containing an optional gateway (24) and a plurality of gatekeepers (GK) to a wireless terminal (18) in one of a plurality of wireless systems. A method in accordance with the invention includes processing information relating to the communication to determine at least one area in which the communication is to be broadcast to the wireless terminal; identifying from the at least one area at least one associated destination gatekeeper to which a message should be transmitted from the gateway to initiate the communication and to which the communication is transmitted; transmitting the message from the gateway to the at least one associated destination gatekeeper; and transmitting the message from the at least one associated destination gatekeeper to at least one of the plurality of wireless systems.

Abstract: An asymmetric network system manages bandwidth allocation and configuration of remote devices in a broadband network. A modular architecture of the system permits independent scalability of upstream and downstream capacity separately for each of the upstream and downstream physical paths. Allocation of downstream bandwidth to requesting devices is made according to bandwidth utilization by other devices, bandwidth demand by the requesting remote device, class or grade of service by the requesting remote device or bandwidth guaranteed to other remote devices.

Abstract: A method and concomitant apparatus for incorporating one or more relatively low bitrate information streams (e.g., MPEG) into a relatively high bitrate information stream (e.g., SDTI) in a manner aligning low bitrate sub-stream splice entrance points and splice exit points within the frame boundaries of the high bitrate information stream. In this manner, the splicing of the relatively high bitrate information stream at appropriate In Frames and Out Frames will provide relatively seamless splicing of information sub-streams. The packing and unpacking methods are implemented such that the temporal offset between elementary streams carried within relatively low bitrate information stream is removed, i.e., the elementary streams are synchronized.

Abstract: ATM cells inputted into a physical layer interface (12) are once stored in a cell buffer (24) regardless whether they are ATM cells to be outputted from a switching interface (22) or ATM cells addressed to host CPU (26), and the ATM cells addressed to the host CPU are stored in a temporary RAM (18) at a timing controlled by a scheduler (16). The host CPU 26 read out ATM cells stored in the temporary RAM (18) when necessary. Thereby, no FIFO memory is needed to temporarily store ATM cells addressed to the host CPU (26).

Abstract: A technique for dynamically assigning a packet flow to transmission channels can result in more efficient use of the channels when compared to static assignment techniques. Using this technique for dynamic assignment, an initial channel assignment is made based upon a channel specification corresponding to a flow classification indication within the first packet of the flow. Subsequently, the flow classification indications of further packets within the flow are monitored for changes. If it is detected that a flow classification indication has changed when compared to the previous flow classification indication, it is determined whether the previous channel assignment satisfies a channel specification corresponding to the new flow classification indication. If it is determined that the previous channel does not satisfy this new channel specification, a modified channel assignment is generated for the subsequent packets of the flow.

Abstract: A method and system for determining a source radio frequency impairment in a data-over-cable system. The method includes ascertaining reference signal-to-noise ratios and comparing them to signal-to-noise ratios that are measured when the system is in operation. The signal-to-noise ratios are measured under different selections of which cable modems transmit. The method determines whether there are degradations on one or more upstream channel and correlates the degradations to identify the source of the impairment. The identification of impairments helps ensure that the source of impairment may be removed from the data-over-cable system to provide better overall performance.

Abstract: A mobile node moves from a first IP (Internet Protocol) network to a second IP network in a network system in which the first IP network capable of executing communication in accordance with both first and second kinds of IPs and the second IP network capable of executing communication in accordance with only the first kind of IP are connected with each other. When the mobile node communicates a message with other nodes on the first network after its movement accordance with the second kind of IP, a header for the movement containing both home and foreign addresses of the first kind in IP is added to a header containing home and foreign addresses in the second kind of IP, and put to the message, is added. The message to which the movement header is thus added is used for the communication between a first mobile agent on the first network and a second mobile agent on the second network, or between the mobile node and the first mobile agent.

Abstract: Methods and apparatuses for supporting both Internet Group Management Protocol (IGMP) and GARP (Generic Attribute Registration Protocol) Multicast Registration Protocol (GMRP) multicast registration concurrently are disclosed. IGMP registrations are processed by one or more network routers. The IGMP registrations are passed to one or more switches and processed by the one or more switches as GMRP static registrations.

Abstract: A signalling point of a telecommunications network comprises a Transport Independent Call Control (TICC) part 4. A signalling transport part 6 is arranged to exchange call control signalling information with the TICC part 4 and with a peer TICC part at a remote signalling point. A signalling transport converter 5 is arranged logically between the TICC part 4 and said signalling transport part 6 and is arranged to present a standard interface to the TICC part 4 and a specific interface to the signalling transport part 6, wherein said call control signalling is exchanged between the TICC part 4 and the signalling transport part 6 via the signalling transport converter 5.

Abstract: A system and method for modifying the spectrum allocation for DSL and LAN signals in accordance with bandwidth requirements of a small office, home office (SOHO) network is disclosed. After initiation of computers within the SOHO network, a handshake procedure is performed between the SOHO network and a wide area network (WAN). The handshake procedure discloses bandwidth requirements for the SOHO network to perform local communication between local area networks (LANs), and for the SOHO network to communicate with the WAN. As a result, the system modifies the spectrum allocation for digital subscriber line (DSL) and LAN signals associated with the SOHO network such that maximum bandwidth allocation is provided in accordance with actual bandwidth need.

Abstract: A SDH signal generation portion generates and outputs an SDH signal by increasing/decreasing the AU point values contained in the SDH signal, using a sequence pattern made of a plurality of arbitrary combinations of basic patterns, a single basic pattern being made of changing the AU pointer values successively for a predetermined repetition number of times with the same increase/decrease type and repetition cycle. A memory stores in a different memory area for each basic pattern, taking the increase/decrease type, repetition cycle and repetition number of times as one set of basic pattern information, for basic patterns used in the SDH signal generation portion, and, stores an address designating a memory area storing the basic pattern information of the basic pattern following its own basic pattern for respective basic pattern.

Abstract: A method of detecting a transmission rate in a wireless communication terminal employing a Code Division Multiple Access (CDMA) scheme, comprising the steps of: decoding and encoding, at a selected transmission rate, a frame signal corresponding to a data frame currently received by a de-interleaver from a modulator-demodulator (modem) in response to the reception of the data frame; comparing the encoded frame signal with the current frame signal being received from the modulator-demodulator, and as a comparison result, determining whether there are errors in an amount less than a predetermined threshold value; transmitting a signal indicative of the selected transmission rate to a vocoder if there are errors in an amount less than the predetermined threshold value, and determining whether the reception of all data frames is complete; returning to the encoding and decoding step if the reception of all data frames is not complete; and, selecting another transmission rates other than the previously selected tra

Abstract: A system and method are provided for encoding and decoding a bitstream according to the High level Data Link Control protocol (HDLC) without having to analyze the bitstream bit by bit. An optimized encoder and an optimized decoder are provided. Both encoder and decoder analyze their respective input streams by using a number of bits in parallel as an index into a table, the contents of which control an action by the encoder or decoder that emits in parallel a number of output bits.

Abstract: In a discrete tone system, a base station receives a transmission burst from a remote unit being installed that includes delay compensation pilot tones that are uniformly spread throughout the transmission bandwidth. The arrival time transmission burst is not synchronized with the other remote units transmitting to the base station. The base station measures the phase delay of each tone and calculates the delay of the remote unit from the slope of the line of phase angle versus tone frequency. The base station transmits a signal to the remote unit that includes the magnitude and direction of the delay, which allows the remote unit to adapt the timing of its transmission to be synchronized with the other remote units.

Abstract: The invention uses a novel signaling protocol for conducting call waiting-caller ID messaging. Instead of waiting for an acknowledge back from the caller ID box, an acknowledge signal is generated locally at a gateway. This allows the packet switched network to meet the timing requirements of the circuit switched network. The gateway tricks the central office switch into believing an actual acknowledge signal was sent from the caller ID box. The central office switch accordingly sends the caller ID information. This ID information is then propagated across the IP network to the caller ID box.

Abstract: The invention relates to an optical system in the ray path of a confocal fluorescence microscope, comprising at least one laser light source (1, 2), a device positioned in the illuminating/detecting beam (3, 4, 5) for separating the exciting light (8) from the fluorescent light (9), an objective (10) arranged between the device and the object (7), and a detector (11) positioned downstream of the device situated in the detecting beam (5). The aim of the invention is to increase the fluorescence yield of the system while retaining its compact structure.

Abstract: A process for operation of a laser device (1) is described, whereby circulating light pulses each comprising spectral components according to a plurality of longitudinal modes of a resonator configuration (3) are generated in the resonator configuration (3) and subjected to a compensation of group velocity dispersion, and a predetermined linear dispersion is introduced into the light path of the resonator configuration (3), so that at least one mode has a predetermined frequency and/or the mode distance between the modes has a predetermined value. Furthermore, regulations for stabilizing the laser device on the basis of this process and applications of the regulations for the generation for stabilized, ultra-short light pulses, generation of optical frequencies and in the frequency and/or time measuring technique as well as in the spectroscopy are described.

Abstract: A waveguide device in the form of either a solid-state laser or amplifier is divided into separate pumping and output mode control sections along at least one direction of the device by leaving a portion of a core of the device unclad or by depositing appropriate coatings on different sections of the core or by contacting/bonding materials with different refractive indices to different sections of the core or by a combination of these approaches. The core has a pump input surface for receiving pumping radiation at a pumping wavelength and one or more output surfaces for emitting a laser beam at an output wavelength. When used as an amplifier, the core also has a laser input surface which may be the same as one of the output surfaces.

Abstract: The preferably highly antireflection coated facet of a laser chip is imaged by an optical system onto a reflector, as a result of which the adjustment tolerance is substantially increased by the cat's eye effect and, since the optical system is provided with a high longitudinal chromatic aberration, the wavelength can be tuned by shifting given parts of the total system relative to other parts of the total system. In this way a tunable semiconductor laser light source which is free from mode jumps and has at most two adjustable degrees of freedom can be produced.

Abstract: A wavelength-tunable stabilized laser is provided with a light source comprising a plurality of lasers capable of oscillating at a plurality of wavelengths, a light detecting part for detecting the light intensity of laser light output from the light source via a periodic filter, and a controlling part for generating oscillation of one of the lasers of the light source and controlling the oscillation wavelength of the laser so that the output value of the light detecting part becomes equal to a predetermined one of a plurality of target values. The wavelength-tunable stabilized laser is able to generate oscillation of laser light at a desired wavelength, of the plurality of wavelengths, and to stabilize the wavelength.

Abstract: A method for the self-calibration of a tunable, diode pumped solid state laser in which the frequency or the wavelength of the laser radiation of the fundamental frequency and/or doubled frequency is changed by of changing the optical cavity length by means of a piezo-actuator or Brewster window over the total amplification bandwidth of the laser-active material. According to the method, the performance curves during the tuning of an etalon or corresponding optical elements arranged in the cavity are recorded and stored and a tuning function for the respective optical element or optical elements is generated (derived) from these curves by a microcontroller or computer. An optimum working point for the optical element or optical elements for maximum suppression of side modes is adjusted by a digital or analog regulator with the help of a learning curve (learning characteristic).