306results about How to "Reduce repetition rate" patented technology

A method for precise working of material, particularly organic tissue, comprises the step of providing laser pulses with a pulse length between 50 fs and 1 ps and with a pulse frequency from 50 kHz to 1 MHz and with a wavelength between 600 and 2000 nm for acting on the material to be worked. Apparatus, in accordance with the invention, for precise working of material, particularly organic tissue comprising a pulsed laser, wherein the laser has a pulse length between 50 fs and 1 ps and with a pulse frequency of from 50 kHz to 1 MHz is also described.

A source of pulses of coherent radiation at a wavelength of approximately 1 μm, comprises a pump source for producing pump light, a laser cavity comprising an Yb3+-doped gain medium arranged to receive the pump light, the laser cavity being modelocked to generate laser pulses at a defined repetition rate; a pulse detector arranged to generate a pulse selection signal indicative of the repetition rate; a pulse selector arranged to reduce the repetition rate of the laser pulses responsive to the pulse selection signal from the pulse detector by passing only selected ones of the laser pulses; and at least one optical amplifier for amplifying the laser pulses of reduced repetition rate. The at least one optical amplifier can be configured for chirped or parabolic pulse amplification.

Dose uniformity of a scanning ion implanter is determined. A base beam current is measured at the beginning and / or the end of a complete scan over the whole substrate area. This base beam current is measured at a time when the measurement should be unaffected by outgassing from a substrate being implanted and a base dose distribution map is then calculated for the scan in question. During the scan itself beam instability events are detected and the magnitude and position in the scan of the detected instability events is measured. Corresponding deviations in the calculated base dose map are determined and subtracted from the previously calculated base dose distribution map to provide a corrected distribution map. By determining overall dose uniformity substractively in this way, good overall accuracy can be obtained with lesser accuracy in the measurement of the beam instability events.

An optical pulse source comprising a DPSS pump laser, a photonic crystal fiber (PCF), and acousto-optic modulator (AOM) gating device is disclosed. The pump pulses are coupled through lenses to the AOM gating device, which is synchronized to the pump laser and is operable to gate the pump pulses to a reduced repetition rate Rr=Rf / N, where Rf is the pump laser fundamental frequency. The pulses from the AOM are injected via optics into the PCF. Propagation through the PCF causes the pulses to broaden spectrally to produce optical supercontinuum pulses. An optical pulse source that further includes an acousto-optical tunable filter (AOTF) operable to convert the optical supercontinuum pulses into wavelength variable output pulses is also provided. A method of scaling the energy of the optical supercontinuum pulses is also disclosed.

The invention discloses a path planning algorithm of a mowing robot. The mowing robot comprises an electronic control device, a camera system and a GPS (Global Position System) positioning module, wherein the electronic control device is used for setting a processor, the processor is used for setting the path planning algorithm, and the path planning algorithm comprises the following steps of: 1, obtaining the position data of a charging seat, starting off by starting a mowing motor, searching a lawn natural boundary leftwards through the camera system, then walking forwards along the lawn natural boundary, and collecting forward images in real time; 2, obtaining the lawn natural boundary and positioning piles from the images by the processor, and walking forwards along a non-natural boundary formed by the natural boundary and the positioning piles until walking back to the position of the charging seat; 3, starting to search a mowing boundary by the mowing robot, starting to work along the mowing boundary, working towards the center of a lawn circle by circle; and 4, judging that the mowing task is finished when the mowing robot cannot find mowing boundary, shutting down the mowing motor, and walking back to the position of the charging seat.

A method and a device for adaptively controlling power in a radar device having a radar transmitter and a radar receiver are provided, in particular for applications in vehicles. The radar signals are emitted, and radar signals reflected off of target objects are received and checked for irregularities. The transmitting power of the radar transmitter is reduced when irregularities occur which are attributable to interference caused by neighboring radar transmitters.

A Personal Locator Beacon (PLB), supporting two operation modes local monitoring and remote monitoring. The apparatus includes a PLB that supports the present operation mode, as well as a local monitoring mode, employing the same transmitter, and automatically switching between modes. Upon activation, the PLB first tries to communicate with a local monitoring station, at a low transmission power, and at a high repetition rate, in purpose of dealing with the PLB call locally, without involving the remote monitoring station. Then, if not acknowledged by a local monitoring station, the PLB increases its transmission power, enabling access to a remote monitoring station. In a preferred embodiment, the PLB is carried by a person onboard a vessel, to alarm upon a Man Overboard (MOB) accident, the local monitoring station is installed onboard the same vessel, and the remote monitoring station is part of a satellite Search and Rescue (SAR) system, as Cospas-Sarsat.

Systems and methods employing Coherent Raman Scattering (CRS), e.g., Coherent anti-Stokes Raman Spectroscopy (CARS) and / or Stimulated Raman Scattering (SRS) are provided. Systems and methods for performing flow cytometry, imaging and sensing using low-resolution CRS are also provided.

The invention discloses a design method of a full-coverage traversal path planning algorithm of a cleaning robot. The design method of the full-coverage traversal path planning algorithm of the cleaning robot comprises the following main processes of generating a traversal cleaning trajectory in a rectangular region by utilizing a Standard chaotic equation, decomposing a to-be-cleaned region into rectangular sub-regions, constructing rectangular iterative sub-regions, constructing an optimal sub-region joining path, constructing rectangular transition sub-regions and repeated sub-regions, constructing an optimal full-coverage traversal cleaning connection diagram, automatically joining the iterative sub-regions, and realizing a full-coverage traversal cleaning task in a feasible region. The algorithm of the design method of the full-coverage traversal path planning algorithm of the cleaning robot is low in repetitive rate and high in coverage rate; a cleaning blind area does not exist; the algorithm is high in planning efficiency; a start point and an end point are not needed to be determined; and the algorithm is simple and is easy to realize. By using the design method of the full-coverage traversal path planning algorithm of the cleaning robot, the indoor cleaning by the robot can be met quite well and the task of planning the full-coverage traversal path is realized.

System for converting relatively long pulses from rep-rate variable ultrafast optical sources to shorter, high-energy pulses suitable for sources in high-energy ultrafast lasers. Fibers with positive group velocity dispersion (GVD) and self phase modulation are advantageously employed with the optical sources. These systems take advantage of the need for higher pulse energies at lower repetition rates so that such sources can be cost effective.

A source of pulses of coherent radiation at a wavelength of approximately 1 μm, comprises a pump source for producing pump light; a laser cavity comprising an Yb3+-doped gain medium arranged to receive the pump light, the laser cavity being modelocked to generate laser pulses at a defined repetition rate; a pulse detector arranged to generate a pulse selection signal indicative of the repetition rate; a pulse selector arranged to reduce the repetition rate of the laser pulses responsive to the pulse selection signal from the pulse detector by passing only selected ones of the laser pulses; and at least one optical amplifier for amplifying the laser pulses of reduced repetition rate. The at least one optical amplifier can be configured for chirped or parabolic pulse amplification.

The present invention provides compositions for bowel cleansing that have improved palatability through the inclusion of a sweetener, such as a chlorinated sucrose isomer. The invention also provides methods of reducing the saltiness of an orally consumed substance, including phosphate salt and PEG / salt bowel cleansers, through the use of a sweetener. Utilizing a sweetener including Sucralose to reduce the saltiness of a substance unexpectedly contradicts the conventional belief that sweeteners amplify saltiness.

System for converting relatively long pulses from rep-rate variable ultrafast optical sources to shorter, high-energy pulses suitable for sources in high-energy ultrafast lasers. Fibers with positive group velocity dispersion (GVD) and self phase modulation are advantageously employed with the optical sources. These systems take advantage of the need for higher pulse energies at lower repetition rates so that such sources can be cost effective.

The invention discloses a robot full-coverage path planning method and device based on a raster map as well as equipment. Firstly, the whole environment map is divided into multiple simple adjacent subareas, then, each subarea is traversed, and the repetition rate is very low while the coverage rate is high. Besides, in the traversal process, the walking state is changed in real time according topositioning information and map barrier information, and the method has the advantages of being simple, flexible and easy to implement. In addition, when a robot is in a cleaning area, the main running direction of the robot directly affects the turn times of paths. The main direction of the areas is used as the main running direction of the robot for traversing the cleaning paths, so that the turn times of paths is greatly reduced, and the traversal efficiency is improved.

The present invention discloses a low-energy loss robot full coverage path planning method and system. The system comprises a robot, a ranging sensor, an encoder and an IMU. The method comprises: establishing an environment grid map by using an instant positioning and map construction algorithm; preprocessing a grid map, and adjusting a resolution and a reachable cleaning area of the grid map; defining the energy loss cost function of a mobile cleaning robot full coverage path, and calculating an optimal grid map segmentation direction by using a finite heuristic search algorithm; using the segmentation direction to perform area segmentation on the grid map through each vertex in the grid map; performing matching detection on the adjacent segmented areas, and combining the segmented areaswith a higher matching degree into a segmentation area; and determining a traversal direction according to the map segmentation direction, and sequentially traversing each segmentation area to plan afull coverage path. According to the technical scheme of the present invention, the concave polygon is segmented into convex polygons, so that planning an arch full coverage path can be facilitated, and the cleaning efficiency is greatly improved.

A method and devices are disclosed, for tracking a radio beacon from a moving device, while the beacon transmits periodic signals, which the device detects at least at two different locations, and the device provided with information enabling determining the time difference between transmissions of these periodic signals. The method discloses a formula for estimating the angle between the course of the moving device and the beacon: ar cos [c*(TDOA12−TDOT12) / baseline12]; wherein the moving device detects signal 1 and signal 2 respectively at location 1 and location 2, the distance between these locations defined as baseline12, TDOA12 is the Time Difference of Arrival of the signals at the two locations, TDOT12 is the time difference between transmission of these signals, and c is the speed of light.

The invention relates to a high-energy low-repetition-frequency fiber laser, which comprises a pump light source used for providing energy for generating laser light, a gain fiber used for providing gains, a mode locking device used for modulating the laser light so as to generate ultrashort pulses, and a single-mode transmission fiber used for laser transmission, wherein the gain fiber, the single-mode transmission fiber and the mode locking device form a resonant cavity of the fiber laser; the generated laser light is oscillated in the resonant cavity; and under the condition that the lengths of the gain fiber and the mode locking device are not increased, the length of the single-mode transmission fiber is increased according to a relation that the length L of the resonant cavity is inversely proportional to the repetition frequency frep of the fiber laser and according to the reduction of the needed repetition frequency frep. By increasing the length of the resonant cavity, the high-energy low-repetition-frequency fiber laser reduces the repetition frequency of pulses in the resonant cavity, correspondingly improves the energy of a single pulse, further simplifies the structure of an amplification system, improves the efficiency of an amplifier and effectively reduces the cost.

A new packaging method for a wide range of MEMS for application on both the wafer and device scale. Titanium is used as the packaging material and both silicon and titanium MEMS devices are integrated on to a titanium substrate. A Nd:YAG pulsed laser is used to micro-weld the titanium cap to the substrate. A three-dimensional time dependent model of heat flow during laser beam welding is presented. The heat transfer and parametric design capabilities of COMSOL were employed for this purpose. Model calculations are compared and calibrated with experimental results of pulsed laser welds. The functionality and hermiticity of the proposed packaging was evaluated by packaging a self actuated Veeco Instrument AFM cantilever tip. The experimental measurements show that the resonance frequency and quality factor of the device stay the same before and after packaging and the applied technique has no effect on the device.

A method is provided for selectively transmitting stop sign intersection data to a vehicle in an infrastructure-to-vehicle communication system. The infrastructure-to-vehicle system includes a fixed entity for broadcasting wireless messages to vehicles in a predetermined area. The local intersection data is broadcast from a local intersection device at a first repetition rate. The local intersection data relates to the intersection in which the vehicle is currently approaching. Remote intersection data, such as map GID, is broadcast from the local intersection device at a second repetition rate. The remote intersection data relates to intersections beyond the vehicle's current approaching intersection. The second repetition rate is lower than the first repetition rate.

An optimized Yb: doped fiber mode-locked oscillator and fiber amplifier system for seeding Nd: or Yb: doped regenerative amplifiers. The pulses are generated in the Yb: or Nd: doped fiber mode-locked oscillator, and may undergo spectral narrowing or broadening, wavelength converting, temporal pulse compression or stretching, pulse attenuation and / or lowering the repetition rate of the pulse train. The conditioned pulses are subsequently coupled into an Yb: or Nd: fiber amplifier. The amplified pulses are stretched before amplification in the regenerative amplifier that is based on an Nd: or Yb: doped solid-state laser material, and then recompressed for output.

The invention relates to a general file searching system which comprises: resource searching unit, results page formation unit, resource verification unit, resource database, resource regulation unit, searching database, indexing unit, feedback unit and resource update unit. The invention also relates to a general file searching method which is characterized in that: verifying validity of resources and regulating them, as well as searching media resource from internet; in all resources matched with key words, selecting the most effective, non-repeat resources and returning back to users, optimizing searching results via feedback units and removing invalid searching results.

The communication apparatus employing the non-coherent scheme is used in the UWB-impulse radio system. In order to make it possible to reliably realize long-distance communication, while observing the reference values of the average radiation power and the peak radiation power, and also to realize high-speed short-distance communication, the apparatus includes an impulse adjusting unit which adjusts, according to the distance between two communication apparatuses detected by the distance detecting unit, the amplitude and the repetition frequency of impulses used in radio communication between the two communication apparatuses.

An optical parametric oscillator (OPO) comprises a resonant cavity for signal light, and an optically non-linear medium disposed in the resonant cavity for converting pump light into the signal light, wherein the resonant cavity is arranged so that in operation signal light is repeatedly output from and returned to the optically non-linear medium along a signal light path in a continuously repeating cycle, and the OPO comprises delay means for extending the time taken for signal light output from the optically non-linear medium in operation to return to the optically non-linear medium along the signal light path.

An ear-plug alarm comprises a base station which sets the time, and ear-piece which provides autonomous timing and alarm functions after it is disconnected from the base station. The base station is implemented in personal computer software with an appropriate interface. Each ear-piece stores its own alarm setting, and operates autonomously after it is disconnected, so that a single base station can support any number of ear-pieces. With this method the alarm becomes a count down from the time that it is set, relieving the ear-piece timer of any long-term accuracy requirement.

Still picture images are encoded and transmitted at reduced rates using the MPEG-2 standard. Video frames are captured for processing at a still picture capture rate that is lower than the video input frame rate. The captured frames are compressed as Intra frames at the input frame rate. Selected ones of the compressed frames are inserted in the MPEG-2 transport stream for communication to a decoder at a still picture repetition rate which is no less, in frames per second, than the capture rate.

The invention discloses a MHz photonic crystal fiber ultra-short pulse laser based on a multichannel pulse compressor. The laser comprises a diode pumping source, a photonic crystal fiber, an intra-cavity pulse compressor, a semiconductor saturable absorber mirror and an extra-cavity pulse compressor, wherein the inter-cavity pulse compressor and the extra-cavity pulse compressor respectively are an intra-cavity multichannel pulse compressor and an extra-cavity multichannel pulse compressor. The main bodies of the multichannel pulse compressors are end mirrors in which two concave spherical surfaces are coaxially and oppositely arranged, each end mirror is provided with a rotating ring, and a concave spherical reflector is arranged in the rotating ring. The MHz photonic crystal fiber ultra-short pulse laser has the advantages that the low recurrence frequency of the pulse laser greatly reduces heat accumulation of pulse on components and prolongs the service life of the components, meanwhile, the intra-cavity multichannel compressor and the extra-cavity multichannel compressor with low loss and compact structure overcome the disadvantages of other chromatic dispersion compensation technologies, and the ultra-short pulse laser with low cost, high energy and high peak power output is realized.

The invention discloses a repeated data deleting method and device, and improves system reliability of a mobile intelligent terminal. The method comprises the steps of: carrying out matching on a data fingerprint of a current data block and data fingerprints in a hotspot hash table, and if a matching result is that the data fingerprint of the current data block is consistent with one data fingerprint in the hotspot hash table, determining the current data block as repeated data; and if a matching result is that the data fingerprint of the current data block is inconsistent with the data fingerprints in the hotspot hash table, carrying out matching on the data fingerprint of the current data block and data fingerprints in a hash fingerprint table, and when a matching result is that the data fingerprint of the current data block is consistent with one data fingerprint in the hash fingerprint table, determining the current data block as the repeated data, wherein the data fingerprint of each harsh table item in the hotspot hash table is a data fingerprint of which repeated times in at least one file reach a set threshold value, and the data fingerprints of the hash fingerprint table are stored data fingerprints of all the data blocks.

A novel symmetric key algorithm for high speed encryption comprises an encryption algorithm and a decryption algorithm, wherein the encryption algorithm comprises the following steps: grouping plaintexts M to obtain Mi; generating basic keys R1 and R2 by using a random number generator; collecting statistics about a plaintext length L, and filling Mn-1 with plaintext, that is, firstly filling a binary key generator identification code, calculating remaining bits, and filling with random binary code; getting a key offset generator G; encrypting a Mn-1 plaintext group; obtaining an encrypted key Keyi; encrypting all the plaintext groups; encrypting the basic keys R1 and R2, to obtain a cipher key CR; and completing the encryption, and transmitting the obtained ciphertext. The novel symmetric key algorithm has the advantages that the probability of key repetition is zero, and the encryption subkey of each plaintext segment is unique and random, so that the security is high; and the encryption speed is fast, that is, only two offsets, two modular operations, one multiplication, two additions, one judgment, two different or same 10-step basic operations are needed.

A fiber Chirped Pulse Amplification (CPA) laser system includes a fiber mode-locking oscillator for generating a laser and stretching into a few hundreds ps-10 ns pulse by a fiber stretcher for projecting into an acoustic-optic (AO) functioning as a pulse picker for generated a modulated laser with a reduced repetition rate for projecting to a multiple stage amplifier. The multiple stage amplifier further includes a first high-energy amplifier implemented with a large mode area (LMA) fiber for amplifying the modulated laser up to a uJ level laser and a second amplifier implemented with a PCF based Yb doped fiber to further amplify the uJ level laser to a mJ level laser.