Abstract: A repeat use data inserting apparatus for repeatedly inserting repeat use data into program data in accordance with appropriate timings. The apparatus comprises a data holding unit and a data multiplexing unit. The data holding unit holds the repeat use data made of a plurality of material data in the form of separately encoded streams. The data multiplexing unit multiplexes separately encoded streams of a plurality of material data constituting the program data during a period other than a data insertion period during which the repeat use data is inserted into the program data. The data multiplexing unit further inserts repeatedly the repeat use data into the program data during the data insertion period by multiplexing the separately encoded streams of the plurality of material data constituting the repeat use data held in the data holding unit.

Abstract: A system and method for performing interleaved packet processing in a network router. A packet to be routed includes a source address bit pattern and a destination address bit pattern that are each processed by a task processor in accordance with a data tree. The data tree includes multiple nodes linked by branches wherein an instruction that is associated with each node within the data tree is utilized for determining which branch is to be taken in accordance with the source address bit pattern or the destination address bit pattern. A first bank of registers is utilized to load an instruction to be executed by said task processor at each node of the data tree in accordance with the source address bit pattern. A second bank of registers is utilized for loading an instruction to be executed by the task processor at each node of the data tree in accordance with the destination address bit pattern.

Abstract: A multi-layer class identifying communication apparatus, includes an input interface connected to input communication lines; a switch circuit; and an output interface connected to output communication lines. The input interface comprises an allocating section which determines a class identifier indicative of one of classes to which an IP packet belongs, from header data of the IP packet received through one of the input communication lines, and allocates an IP-QOS (Internet-Protocol-Quality-of-Service) code to the IP packet. The switch circuit selects one of the output communication lines based on a destination address of the IP packet, such that the IP packet is outputted from the output interface to the selected output communication output interface.

Abstract: A system and method for merging multiple connections that share a same class of service into a single virtual circuit (VC) connecting a first switching node to a second switching node in an Asynchronous Transfer Mode (ATM) network. In accordance with the system of the present invention, a data buffer stores cells that constitute a packet received by a switching node. A queuing apparatus includes multiple connection queues associated respectively with each of the connections, and further includes a scheduled queue corresponding to a particular class of service, wherein contents of the connection queues are transferred into the scheduled queue before being transmitted on the VC. A reassembly queue control block (RQCB) is associated with each of the connection queues, and defines a chain of buffer control blocks. Each buffer control block corresponds to a cell belonging to a packet transmitted in a particular connection.

Abstract: A packet switch device having a plurality of input buffers; a packet switch; a plurality of schedulers, having a pipeline scheduling process module wherein a plurality of time units corresponding to the number of output lines is spent in scheduled sending process of the fixed length packets from the input buffer, and wherein the scheduled sending process is executed in a number of processes, in parallel, the number of processes corresponding to the number of the input lines, having a sending status management module wherein sending status of the fixed length packets which constitute one frame is managed for each of the input lines, and provided corresponding to any of the output lines; and at least one result notification module for notifying the input buffer of result information from the scheduled sending process performed by each of the plurality of schedulers.

Abstract: Input buffer type packet switching equipment, which can output cells to an external output line having a slower output line rate than a corresponding input line rate without having buffers in its output line sections, is provided. The input buffer type packet switching equipment provides M input line buffers that store cells inputted from M input lines temporarily in a state that one of the M input line buffers stores cells inputted from corresponding one of the M input lines, in this the M is an integer being 2 or more, an M×N crossbar type switch, which provides N output lines, for switching cells outputted from the M input line buffers based on a cross point on/off control signal, in this N is an integer being 2 or more.

Abstract: An add/drop cross connection apparatus of an SDH system, comprises an aggregate unit matching device for providing matching with the aggregate units, a higher order path connection circuit for subjecting received higher order path data to cross connection by space switching, a lower order path connection circuit for subjecting received lower order path data to cross connection by space switching, and a selector for selectively delivering the data supplied from the aggregate units, higher order tributary device, and lower order tributary device, wherein the selector delivers the data to the higher order path connection circuit or lower order path connection circuit according as the data is the higher or lower order path data.

Abstract: A packet receiving-transmitting method is provided for use on a packet-switching network, such as Ethernet, for the purpose of handling packets more efficiently than the prior art. By this method, each received packet is stored in a packet buffer of a fixed size and associated with just one descriptor. Based on a threshold determined by the network protocol, each packet buffer is partitioned into a plurality of segments, each having an ending point linked to an Early Receive/Transmit interrupt signal with the ending point of the packet buffer being linked to an OK interrupt signal. In response to each Early Receive/Transmit interrupt signal, the packet data stored are retrieved and forwarded; and in response to the OK interrupt signal, all the remaining packet data in the packet buffer are retrieved and forwarded. After this a write-back operation is performed on the associated descriptor so as to reset the descriptor to unused status.

Abstract: In a method of managing call collisions, in the event of a bit rate collision or a logical channel collision occurring at the time of a request to set up a call between a first terminal and a second terminal, one terminal is designated the master terminal and the other terminal is designated the slave terminal. Depending on the source of the call request packets, the two calls are automatically transmitted via the signaling channel or a data channel.

Abstract: An address management apparatus comprises a data link layer address storage unit for storing a data link layer address table showing the correspondences between data link layer addresses and network layer addresses; a data link layer address search unit for searching the address table for an unused data link layer address; a corresponding network layer address search unit for searching the address table for a network layer address corresponding to a specified data link layer address; a data link layer address assignment instruction unit for transmitting a data link layer address assignment instruction which includes, as information, at least the unused data link layer address, to a terminal specified by the network layer address detected by the corresponding network layer address search unit; a data link layer address updation unit for updating the correspondence between the data link layer address and the network layer address on the address table, according to the data link layer address assignment instruct

Abstract: A digital video recorder or similar apparatus implements a method of converting an input data stream having an MPEG-2 Program Stream (PS) format into an output data stream having an MPEG-2 Transport Stream (TS) format. The input data stream (PS) includes data of at least first and second elementary data streams (404, 406) formed and multiplexed in compliance with a PS decoder model. A scheduler (412) within the apparatus inhibits reading of a further data block from the input stream when, in the absence of a vacancy for data of an audio elementary stream within a target decoder model (418), a clock reference (SCR) of said input data stream advances beyond a clock reference of said output data stream by a predetermined waiting threshold.

Abstract: Data bits—in each case one bit multiplet with a predetermined number of bits per channel—are transmitted in accordance with a particular time sequence in time-division multiplex frames. According to a predetermined allocation of the channels to groups including in each case a predetermined subset of the channels, the multiplets of in each case one group are transmitted time-interleaved with respect to one another in the time-division multiplex frames. The various groups, however, are in each case transmitted successively in the frames.

Abstract: The present invention relates to a method of multiplexing in a multiplexer a plurality of data streams to a single channel each of said data streams containing a plurality of fixed length data packets being serially transmitted from a source to a destination by way of the data stream and the channel, the method comprising:

Abstract: Nondestructive/noncontact evaluation of a material for electrical and magnetic property discontinuities, e.g., a dielectric loss or the presence of a conducting contaminant, is accomplished by using microwaves to heat microwave-absorbing regions of the material caused by such discontinuities; monitoring the change in temperature of the material's surface due to the heating of the microwave-absorbing region as a function of time; and detecting the electrical and magnetic property discontinuities, e.g., the dielectric loss or the conducting contaminant, using the change in the material's surface temperature.

Abstract: A method and apparatus for high rate CDMA wireless communication is described. A set of individually gain adjusted subscriber channels are formed via the use of a set of orthogonal subchannel codes having a small number of PN spreading chips per orthogonal waveform period. Data to be transmitted via one of the transmit channels is low code rate error correction encoded and sequence repeated before being modulated with one of the subchannel codes, gain adjusted, and summed with data modulated using the other subchannel codes. The resulting summed data is modulated using a user long code and a pseudorandom spreading code (PN code) and upconverted for transmission. The use of the short orthogonal codes provides interference suppression while still allowing extensive error correction coding and repetition for time diversity to overcome the Raleigh fading commonly experienced in terrestrial wireless systems.

Abstract: An integrated circuit includes a reconfigurable FIR filter has an input port for receiving digital input signals and an output coupled to a coherent signal processor and a coherent memory. The FIR filter programmably provides filtered signals to the coherent signal processor for storage in the coherent memory. The integrated circuit further includes a sequential weight processor having an input coupled to an output of the coherent memory. The sequential weight processor includes a weight memory and operates to output symbol soft decision data resulting from processing the digital input signals. The integrated circuit is programmable into one of a plurality of operating modes, including at least one of a received signal acquisition mode, a channel estimator mode, an adaptive equalizer mode, and a channel-wise differential mode.

Abstract: A high speed communications system is provided which uses a selectable, desirable portion of the total available bandwidth of a transmission channel. In a preferred embodiment, the invention is an ADSL compatible modem which selects a sub-set of the available downstream DMT sub-channels based on an evaluation of such sub-channels by appropriate signal processing circuitry. An analog front end (AFE) contains sub-band filtering causes an upstream transceiver to use only this selected number of available sub-channels for downstream data transmission. This reduces hardware costs and complexity while still preserving compatibility with applicable ADSL standards and providing a high speed data link. The target data rate of the modem can be further enhanced to the point of achieving fill protocol capability by increasing or upgrading the AFEs, and/or the signal processing circuitry in order to increase the number of processable transmitted downstream sub-channels.

Abstract: The present invention provides an apparatus and method for coding moving pictures, which reduces a delay time generated by buffering of a decoding apparatus in compressive coding of the moving pictures. In this invention, the target number of bits of one picture P as a target value of the number of generated bits per one picture is set as well as the upper limit number of bits uCg as an upper limit value of the number of generated bits of the picture is set. Then, when the cumulative number of generated bits Cg generated from the first macroblock to a macroblock which is being coded in the picture exceeds the upper limit number of bits uCg in the middle of the picture which is being coded, the coding of a macroblock is skipped to avoid underflow.

Abstract: Device and method for decoding a plurality of video bitstreams on the same time by using one decoder by making time multiplexing decoding of bitstreams in different frame rates and film modes in frames, which facilitates simultaneous processing of multiple video bitstreams for PIP, POP, multi-channel broadcasting, and the like by using, not numerous video decoder, but only one HD class video decoded, a required memory size can be reduced significantly, and an IC size can be reduced further if the present invention is applied to an ASIC, that enhances competitiveness.

Abstract: A variable-mode digital logic circuit for accepting a parallel data word of a plurality of data bits wide as input and serializing the word such that the word may be transmitted as output from the circuit over as few as a single one-bit wide trace is provided. The variable-mode digital logic circuit comprises, a plurality of parallel data traces for passing input data to the circuit, each trace dedicated to the transmission of a single bit of the word, a plurality of select-capable MultiPlexor circuits for sequentially activating certain ones of the parallel data traces to pass data thereto and for multiplexing the received data such that the data is serially output therefrom, a ring counter for controlling frequency of specific operations performed within the circuit and at least one additional MultiPlexor circuit array for receiving data output from the plurality of select-capable MultiPlexor circuits as input and for further serializing the received data for output on as few as a single one-bit wide trace.

Abstract: A method and system for encoding data for transmission over a transmission channel in a digital communication system, the method including selecting an appropriate variable length product code for variable length data to be transmitted, and encoding the data by means of the selected product code. The system includes a code selecting unit arranged to select a variable length code which is most suitable for variable length data to be encoded, and an encoder encoding the variable length data with the selected variable length product code.

Abstract: The invention relates to a transmission system via a channel subjected to fading.

Abstract: The invention relates to a method and a device for processing signals of a digital transmission system in general, and for estimating the frequency offset of the transmission system in particular. In one embodiment, the method according to the invention estimates the pulse response of the transmission system and shortens the pulse response by means of a variable prefilter. The duration of the shortened pulse response is, in particular, shorter than the duration of a known symbol sequence which is transmitted twice identically within one method cycle. By comparing samples of the received signal which correspond to the known identical symbols, the frequency offset is estimated reliably, and suitable measures can be taken to compensate it. Consequently, the efficiency of the receiver is substantially improved with respect to the recovery of the transmitted data.

Abstract: This invention relates to a method for the generation of a base band signal (Vp) representative of the power transmitted by a transmitting station. This base band signal is used particularly for controlling the transmission power in a transmitting station. According to the invention, a part (S′) of the radiofrequency signal S transmitted by the transmitting station is extracted and is then mixed with itself to generate a voltage signal (S″) with at least one DC component. The voltage signal (S″) is then filtered and finally amplified using a logarithmic function.

Abstract: A bandpass filter 51 extracts a Nyquist tone signal from an input signal, and a power calculation unit 52 checks the level of the extracted tone signal. A line equalizer control unit 53 controls a line equalizer 42 based on the level of the calculated tone signal. If the level of the tone signal fluctuates beyond a prescribed range, a level adjustment circuit compulsory activation control unit 54 compulsorily activates the line equalizer control unit 53, and if it is judged from the level of the tone signal that the apparatus is in a normal communication state, the level adjustment circuit compulsory activation control unit 54 nullifies the compulsory activation of the line equalizer control unit 53.

Abstract: An all digital PLL-based data detector for use in a disc media reproducer or recorder for receiving input read data read from a disc storage medium and providing an output sync signal and synchronized read data with jitter substantially eliminated. The PLL circuit is provided with a circuit for limiting the fed-back count value to a predetermined range so as to limit the internal sync signal to a desired range, a circuit for resetting a predetermined portion of the digital PLL-based circuit during an invalid period when input read data are expected to be invalid to thereby ensuring a normal operation after the invalid period, and/or a circuit for generating, from a given clock signal of a first frequency, a second clock signal of a second frequency different from the first frequency to thereby support a different data rate.

Abstract: An improved fuel element for use in a nuclear reactor comprised of a central core of nuclear material, which is surrounded by a composite cladding. The cladding has an outer metallic tubular portion comprised of well-known cladding alloys used for such purposes. Metallurgically bonded to the outer metallic tubular portion is a commercially pure zirconium microalloyed with a controlled quantity of iron. The zirconium microalloyed with iron produced an inner metallic barrier having a beneficial balance between stress corrosion crack resistance and corrosion resistance while retaining other beneficial properties of pure zirconium, such as ductility.

Abstract: In order to detect whether the center position of a subject is offset from a scan center and notify a human operator of the result of the detection, the subject center position is detected based on a projection profile of a parallel view at a view angle of 90° (S5). If the distance between the subject center position and the scan center exceeds a predefined range (e.g., 50 cm) (S6), a warning is displayed on a CRT to prompt the operator to adjust the position of the subject and repeat imaging (S7).

Abstract: Driving an X-ray imaging device by applying a high voltage signal to a photo-sensing layer, reading the stored charges that result from dark charges produced by the high voltage signal using a data reader such that stored charges are removed from the charging capacitors, performing X-ray irradiation such that X-ray induced charges are stored in a charging capacitor, and converting the stored charges to electrical signals, all while maintaining the high voltage on the photo-sensing layer. The driving method improves a contrast ratio caused by the dark charges and reduces signal variations caused by turning-off the high voltage before converting the stored charge into electrical signals. As the high voltage turned on and off only one once the driving time can be reduced.

Abstract: An X-ray tube 1 in which a cathode 73 is heated to emit electrons 80, and the electrons 80 are bombarded against an anode target 32, thereby generating X-rays 81, includes a stem substrate 4 mounted on an opening 22 of a container 21 housing the cathode 73, a plurality of pins 5 extending through the insulating substrate 4 and adapted to supply a voltage into the container 21, and pin covers 6 mounted on the pins 5 in the container 21 and arranged at positions away from a surface of the stem substrate 4 to cover base portions of the pins 5.

Abstract: In order to effectively use an angiography arm and a CT gantry and improve examination efficiency, angiographic imaging of a subject Ha in an angiography room Ra and CT imaging of a subject Hc in a CT room Rc are independently performed in one mode. In another, a CT gantry 40 is moved to the angiography room Ra with an X-ray protection door D open, to alternately perform angiographic imaging and CT imaging on the subject Ha in the angiography room Ra in a cycle of, for example, five minutes.

Abstract: A point-of-presence (POP) call center system capable of answering, servicing, queuing and routing of calls at local points of presence to reduce communications costs and enhance operational efficiency for toll-free inbound call centers. The POP call center system includes a set of point-of-presence call center gateways distributed at points of presence close to the point of call origination.

Abstract: Difference compensation circuits are connected to a volume controller having a tap in series. Each of the difference compensation circuit comprises a voltage control amplifier and an external CR network. The difference compensation circuits are arranged so as to independently attenuate a bass range and increase a mid-range in accordance with an amount of volume control by the volume controller.

Abstract: A parametric audio system having increased bandwidth for generating airborne audio signals with reduced distortion. The parametric audio system includes a modulator for modulating an ultrasonic carrier signal with a processed audio signal, a driver amplifier for amplifying the modulated carrier signal, and an array of acoustic transducers for projecting the modulated and amplified carrier signal through the air along a selected projection path to regenerate the audio signal. Each of the acoustic transducers in the array is a membrane-type transducer. Further, the acoustic transducer array is a phased array capable of electronically steering, focusing, or shaping one or more audio beams.

Abstract: An identification system using biometric information of human body parts and a secret sequence code. In particular, biometric information of human body parts is used to form the secret sequence code. Specifically, a combination entry device recognizes user's fingerprints which are entered as a sequence. The fingerprints must be entered in the proper sequence in order to be recognized by the system. The fingerprints are preferably recognized using a fast technique with a low-probability level of rejection. While the sensor can be fooled for any one fingerprint. The use of a plurality of different fingerprints improves the identification capability. In particular, the combination of fingerprints in the proper order is necessary to undo the lock.

Abstract: A time-temporally subtraction-image generating section performs subtraction between corresponding pixels of original images which are objects of comparison and reading. A registration section matches the anatomically characteristic parts of two or more subtraction images obtained through the subtraction process. A display-format setting section arranges and displays the registrated subtraction images on an image display surface.

Abstract: A method of inspecting whether a printed board is appropriately supported by a supporting device, when a holding device holding an electric component mounts the electric component on the printed board supported by the supporting device, the method including the steps of taking, with an image taking device, an image of at least one prescribed detection portion of the printed board supported by the supporting device, and judging, based on image data representing the taken image of the detection portion, whether the printed board is appropriately supported by the supporting device.

Abstract: The present invention discloses a coder and a coding method that raise the possibility of improving the compression ratio of multivalued image data in which one pixel consists of a plurality of bits and are accordingly effective to increase the amount of image that is stored in a recording medium with a certain capacity. The coder according to the present invention includes an obtaining unit for obtaining a predetermined amount of image data in which one pixel consists of a plurality of bits, a developing unit for developing on the virtual plane each piece of the bit data in the obtained image data, and a coding unit for performing the entropy coding on the developed bit data.

Abstract: An image signal read out from an original is binary-coded on the basis of a binary-coding threshold value. The binary-coding threshold value is calculated by making a histogram representing a frequency distribution of tones of the image signal, calculating the value of a peak tone at which the frequency is maximized, calculating as a first tone at which the frequency becomes equal to a predetermined level on the lower tone side of the peak tone, calculating a reference binary-coding threshold value by adding to the peak tone the difference between the first tone and the peak tone, and determining the binary-coding threshold value on the basis of the reference binary-coding threshold value.

Abstract: An apparatus 10 for controlling image quality reduction of image information, which is related to the present invention, has a VLD 30 for introducing a code stream input 21 thereinto of image information based on an MPEG, a reverse circuit 40 for introducing a pre-reverse level 32 thereinto from the VLD 30, and a VLC 50 for introducing a RUN 31 from the VLD 30 and an after-reverse level 42 from the reverse circuit 40, and a code stream output 51 of image information based on the MPEG is generated by the VLC 50 and is sent therefrom, and this code stream output 51 is provided for a digital copy.

Abstract: An object of this invention is to provide a coding method and a coding apparatus for efficiently coding both a pixel value signal and a shape signal which are included in an image signal to be coded, wherein a prediction changing unit outputs a reference pixel value changing signal and a reference shape signal to a switching circuit which selects a reference pixel value signal and to a switching circuit which selects a reference shape signal, respectively, so as to control the switching circuit in a way that appropriate reference signals are to be selected.

Abstract: On the basis of a discrimination parameter for discriminating more detailed brightness in an image, the brightness of the image is discriminated, and the optimum degree of correction component is set for the image, thereby performing a more faithful reproduction of the image indicated by image data. Therefore, a highlight point being a brightness value associated with a cumulative frequency of reaching a predetermined value is calculated in a high-brightness area on the basis of a histogram obtained with respect to the number of pixels of a brightness value indicated by the image data, and the image is discriminated in its entire brightness on the basis of the highlight point. On the other hand, a ratio of the cumulative frequency in a predetermined low-brightness area to the number of all the pixels in the histogram is calculated. On the basis of the calculated ratio and the discriminated brightness, a gamma value indicating degree of correction the brightness value to a value of more light image is defined.

Abstract: An improved wheel bearing unit is composed of an outer race member having two rows of raceway surfaces formed in its inner peripheral surface and attached to the body of a motor vehicle, and an inner race member provided with a wheel mounting flange and rotatably supported through two rows of balls by the outer race member. In the vicinity of the groove bottom portion of the raceway surface of the inner race member is provided a projection having a diameter greater than the inscribed circle diameter. The raceway surface, the outer peripheral surface of the projection, and the smaller end face are concurrently ground to keep within a predetermined range of standard values the radius difference between the diameter of the groove bottom portion of the raceway surface of the inner race member and the outer diameter of the projection, as well as the core deviation between the groove bottom portion of the raceway surface and the smaller end face.

Abstract: A traveling wave optical modulator includes an optical waveguide substrate made of an electro-optic and ferrodielectric single crystal in the form of an X- or Y-orientation plate_and comprising a thicker portion having a larger thickness and a thinner portion having a smaller thickness; first and second branched optical waveguide portions formed at least on the thinner portion of the optical waveguide substrate; a set of electrodes provided on at least the thinner portion of the substrate and adapted for applying voltage to the first and second optical waveguide portions to modulate a light propagating the optical waveguide portions; and a buffer layer provided to cover a part of the optical waveguide portions at the thinner portion of the substrate, the electrodes crossing on the buffer layer.

Abstract: The present invention provides a dense wavelength division multiplexer for separating an optical signal into optical channels. The dense wavelength division multiplexer includes at least one birefringent plate for separating one or more of the plurality of optical channels, where the separating mechanism is at least partially based on the polarity of the plurality of optical channels, and a nonlinear interferometer optically coupled to the at least one birefringent plate for introducing a phase difference between at least two of the plurality of optical channels. In a preferred embodiment, the mechanism of separating includes birefringent beam separation and recombination plates, optical rotation elements, a lens and a non-linear interferometer. The present invention provides an ease in alignment and a higher tolerance to drifts due to the increase in the widths of the pass bands and also provides an improved efficiency of separation of channels.

Abstract: An optical connector ferrule 1A is mounted on the distal end of a fiber optic ribbon cable 2 to form an optical connector Ca. A mating surface 11 of the optical connector Ca opposes an optical connector Cb to be mated. Fiber accommodating holes 13 are formed in the mating surface 11 so as to accommodate optical fibers, and a pair of guide projections 10 are formed on the mating surface 11 so as to be positioned with the optical connector Cb. The ferrule 1A is integrally molded with a resin. This provides an optical connector ferrule allowing the easy manufacturing of an optical connector with good transmission performance.

Abstract: A fiber optic cable (10) having a tube assembly (20) therein. Tube assembly (20) includes an optical fiber group (22) in a tube (21). Optical fiber group (22) comprises a medial optical fiber subgroup (23) and lateral optical fiber subgroups (24a, 24b; 25a, 25b; 26a, 26b) adjacent thereto. Subgroups (24a, 24b; 25a, 25b; 26a, 26b) define a step-like profile for maximizing optical fiber packing density of tube assembly (20) and/or defining a high fiber count cable (10). In exemplary embodiments, a diagonal free space is defined as the tube inner diameter minus the diagonal length of the cross-section of the profile of the optical fiber ribbon stack, the diagonal free space being about 2 mm to about 5 mm. In a multi-tube embodiment, diagonal free space can be about 0.5 mm to about 2 mm. In other embodiments, corner fibers can have a delta optical attenuation of less than about 0.05 dB/Km for a wavelength of @1550 nm over a 100 meter length 40″ to 70″ drum at room temperature.

Abstract: Both wavelength dispersion and a dispersion slope of a line fiber are simultaneously compensated for by combining two types of dispersion compensators having different characteristics.

Abstract: A silica based optical waveguide is described, comprising a substrate, a core waveguide formed thereon, and an over cladding part comprising a silica based glass with a refractive index lowering dopant and a refractive index increasing dopant added, formed on the substrate so as to cover the core waveguide, wherein a segregation layer with a higher concentration of the refractive index increasing dopant is formed in a part of the over cladding part in contact with the substrate and the core waveguide such that at least a part of the refractive index increase in the segregation layer provided by the refractive index increasing dopant with respect to the part of the over cladding part other than the segregation layer is offset by decline of the refractive index by increasing the amount of the refractive index lowering dopant added in the segregation layer and/or adding another refractive index lowering dopant.

Abstract: An optical amplifier with integrated optical waveguide, pump source and other, optional components for amplifying an input optical signal coupled from a fiber optic. The amplifier includes a housing having these components mounted therein, and appropriate optics for coupling the input and output optical signals to and from the appropriate ports, and for carrying an optical pump signal from its source to the waveguide. The optical waveguide disclosed is a channel waveguide amplification chip, having a relatively small size; and the pump source disclosed is a laser diode capable of generating the optical pump signal internal to the housing with only electrical (e.g., power) signals applied thereto from outside of the housing. Other optional components may be provided for cooperative optical processing in the amplifier housing. The disclosed optical amplifier offers size and cost advantages over other known systems.