79 results about "Pulse separation" patented technology

A gas discharge laser crystallization apparatus and method for performing a transformation of a crystal makeup or orientation in the substrate of a workpiece is disclosed which may comprise, a multichamber laser system comprising, a first laser unit comprising, a first and second gas discharge chamber; each with a pair of elongated spaced apart opposing electrodes contained within the chamber, forming an elongated gas discharge region; a laser gas contained within the chamber comprising a halogen and a noble gas selected to produce laser light at a center wavelength optimized to the crystallization process to be earned out on the workpiece; a power supply module comprising, a DC power source; a first and a second pulse compression and voltage step up circuit connected to the DC power source and connected to the respective electrodes, comprising a multistage fractional step up transformer having a plurality of primary windings connected in series and a single secondary winding passing through each of the plurality of primary windings, and a solid state trigger switch; and a laser timing and control module operative to time the closing of the respective solid state switch based upon operating parameters of the respective first and second pulse compression and voltage step up circuit to effect operation of the first and second laser units as either a POPA configured laser system or a POPO configured laser system to produce a single output laser light pulse beam. As a POPA laser system relay optics may be operative to direct a first output laser light pulse beam from the first laser unit into the second gas discharge chamber; and, the timing and control module operates to create a gas discharge between the second pair of electrodes while the first output laser light pulse beam is transiting the second discharge region, within plus or minus 3 ns and as a POPO, combining optics combine the output beams, and timing creates pulse separation in the combined output a preselected time plus or minus 3 ns.

A method for generating nanoparticles in a liquid comprises generating groups of ultrafast laser pulses, each pulse in a group having a pulse duration of from 10 femtoseconds to 200 picoseconds, and each group containing a plurality of pulses with a pulse separation of 1 to 100 nanoseconds and directing the groups of pulses at a target material in a liquid to ablate it. The multiple pulse group ablation produces nanoparticles with a reduced average size, a narrow size distribution, and improved production efficiency compared to prior pulsed ablation systems.

Embodiments of the instant invention are directed to laser exposure system that employs a pulsed solid state laser to provide a reactive response wavelength and a pulse repetition rate specifically optimized for application to solidification of a liquid photopolymer in a stereolithographic process. The solid state laser employs two second harmonic crystals for generating an emission wavelength at about 320-345 nm and a pulse repetition rate, wherein the pulse repetition rate is selected such that a pulse separation at the target surface results which is less than a diameter of the beam when the beam is being scanned at a desired velocity and an average exposure deposited by the beam is equal to a desired amount.

A laser pulse shape measuring system to measure the pulse shape of pulses generated by a pulsed laser. Each pulse includes a pulse width and a peak wavelength. The system includes: a beam splitter coupled to the laser to separate each of the pulses into a test pulse and a probe pulse; a pulse width compression means coupled to the beam splitter to compress the pulse width of each probe pulse; a controllable delay means to control a time offset between each test pulse and a corresponding probe pulse; a nonlinear optical medium arranged such that the test beam path and the probe beam path intersect within it to generate wavelength converted pulses corresponding to intersecting pairs of pulses; a detector coupled to the nonlinear optical medium to detect the pulse energies of the wavelength converted pulses; and a processor to determine the pulse shape of the laser pulses.

The invention provides a stepping motor control system applied to a four-dimensional ultrasonic probe. The stepping motor control system is used for improving the compatibility capacity of an ultrasonic system on the four-dimensional ultrasonic probe. According to the scheme, the stepping motor control system comprises a transmission mechanism connected with an energy converter, a stepping motor, a driver, an FPGA chip and a main processor, and a sine table is generated by the main processor according to subdividing numbers and is sent to the FPGA chip; a pulse separation table is generated by the main processor according to a speed change angle, the scanning angle speed and the stepping angle of the energy converter and is sent to the FPGA chip; a scanning angle is sent to the FPGA chip through the main processor; the FPGA chip controls the driver to output pulse signals according to the scanning angle, the sine table and the pulse separation table, and the stepping motor and the transmission mechanism control the energy converter to rotate. Through the scheme, a CPU in the ultrasonic system can be used for carrying out high-performance data commutating, therefore, control parameters of the four-dimensional ultrasonic probe are provided for an FPGA, and the compatibility capacity of the ultrasonic system on various four-dimensional ultrasonic probes is improved.

In one embodiment, a radio receiver includes: a programmable frequency synthesizer to generate a first clock signal; a first frequency divider to divide the first clock signal to generate a master clock signal; a second frequency divider to divide the master clock signal to generate a mixing signal; and a mixer to downconvert a radio frequency (RF) signal to a second frequency signal using the mixing signal. A voltage converter to couple to the radio receiver includes a switch controllable to switchably couple a first voltage to a storage device and a pulse generator to generate at least one pulse pair formed of a first pulse and a second pulse substantially identical to the first pulse, when a second voltage is less than a first threshold voltage, the second pulse separated from the first pulse by a pulse separation interval.

A method of finding a temporal location of a reflected pulse in a system for remotely measuring characteristics of a target scene. The method includes steps of: (a) transmitting a pulse burst of two or more pulses toward the target scene; (b) capturing a copy of the pulse burst transmitted in step (a); (c) measuring an inter-pulse separation between at least two pulses in the pulse burst captured in step (b); (d) receiving a signal reflected from the target scene; (e) determining a temporal location of a first pulse in the signal received in step (d); and (f) determining a temporal location of a second pulse in the signal received in step (d) based on the inter-pulse separation measured in step (c). Step (a) may include transmitting an OFF-line pulse and at least one ON-line pulse in the pulse burst toward the target scene from a differential absorption LIDAR (DIAL) system, where the OFF-line pulse and the ON-line pulse are combined pulses, each individually generated from a separate pulsed laser transmitter and each having a different wavelength.

The invention discloses a 780 nm high-power optical-fiber femtosecond laser device. The laser device comprises a laser device seed source, a laser spreading and amplifying module, a laser compression module and a laser frequency doubling module, the laser device seed source and the preceding modules are sequentially connected, the laser spreading and amplifying module is composed of a chirped pulse spreading sub module, a pulse separation sub module and an optical fiber amplifying sub module, and the laser device seed source and the modules all work at the waveband of 1560 nm. A mixed pulse spreading mode is adopted, pulses are spread from 100 fs to 1ns in a small work space, the amplified pulses are compressed to below 100 fs through non-linear compression of a single-mode fiber, and ultimately the pulses reach 780 nm after frequency doubling of non-linear crystals. The laser device has the advantages of being high in stability, simple in structure, small and ingenious in size, low in cost and the like.

The invention discloses an overlap kernel pulse separation method, which comprises the following steps: firstly, expressing an original overlap kernel pulse to be separated, which is obtained in radiometry, as the linear sum of N nuclear pulses; then, taking the parameter composition of the N nuclear pulses as a chromosome; and finally, taking the error of the overlap kernel pulse represented by an individual and the original overlap kernel pulse as a target function, adopting the selection, cross and mutation operators of a genetic algorithm, and obtaining an optimal individual after a multi-generation operation so as to obtain the parameter value of each pulse, i.e. realizing the separation of the overlap kernel pulse. When N takes different values, the overlap kernel pulse is subjected to the same separation to obtain new optimal individuals, and the optimal individual with a minimum target function value is selected from the optimal individuals to serve as a final solution. A result indicates that the overlap kernel pulse separation method based on a population searching technology is an optimal combination for searching the kernel pulse from the global meaning to realize the separation of the overlap kernel pulse so as to obtain the parameter of each kernel pulse.

The present invention relates to a single-channel heterodyne distance measuring method. According to the invention, high precision distance measurement may be carried out by the broadcast of pulsed electromagnetic radiation (ES) with at least two pulse repetition frequencies, whereby the pulse repetition frequencies are selected such that the corresponding pulse separations don not have a common multiple in the range of the order of magnitude of a maximum external measurement range. The radiation is hence transmitted both to a target for measurement over the measurement path outside the device and also over a reference path (6) inside the device, whereby the radiation (IS) passing along the reference path (6) defines at least one start pulse and the radiation (ES) passing along the measurement path defines at least one stop pulse. The radiation (RS) back-scattered from the target and the radiation (IS) passing along the reference path are received and converted into a received signal, from which at least one distance to the at least one target is determined. The radiation (RS) back-scatted from the target and the radiation (Is) passing along the reference path (6) are recorded in parallel, such that the received signal comprises components of the radiation (RS) back-scattered from the target sand the radiation (IS) passing along the reference path.

A clock pulse generator for generating at least two clocked pulse signals from a global clock signal is provided. The clock pulse generator includes at least one input for receiving a clock signal having a rising and a falling edge and a mechanism for selectably delaying a rising edge of a pulse signal synchronized to the falling edge of the clock signal. The clock pulse generator further includes a first selectable duration pulse synchronized to the rising edge of the clock signal and a second selectable duration pulse synchronized to the selectably delayed rising edge. The clock pulse generator also includes a glitch avoidance circuit to remove glitches in the clock signal before it is used.

A data communication method for receiving digital data on a data terminal includes receiving data pulses having a first pulse separation to represent a first logical data value and a second pulse separation to represent a second logical data value, generating a voltage ramp signal, resetting the voltage ramp signal a first delay after the leading edge of each data pulse, regenerating the voltage ramp signal a first time period after the resetting of the voltage ramp signal, detecting the voltage value of the voltage ramp signal at the leading edge of each data pulse, and generating a data output signal associated with each data pulse. The data output signal has a first logical state when the voltage value of the voltage ramp signal is less than a threshold value and a second logical state when the voltage value of the voltage ramp signal is greater than the threshold value.

A system for analyzing a sample is disclosed. The system is comprised of a laser unit and a spectrometer unit. The laser unit is configured to emit a first laser pulse and a second laser pulse towards the sample with a pulse separation time of between about 1 microsecond to 20 microseconds. The laser unit includes an oscillator unit, a pre-amplifier unit and an amplifier unit. The oscillator unit is configured to generate the first laser pulse and the second laser pulse. The pre-amplifier unit is configured to receive the first laser pulse and the second laser pulse and increase the energy levels of each pulse to a first energy state. The amplifier unit is configured to receive the first laser pulse and the second laser pulse from the pre-amplifier unit and further increase the energy levels of each pulse to a second energy level prior to the pulses being emitted from the laser unit. The spectrometer unit is configured to capture emissions generated by the sample after the sample is struck by the first and second laser pulses then characterize the sample using the emissions.

The invention relates to an igniter for a motor vehicle, in particular to a digital direct-current igniter for a motorcycle. The digital direct-current igniter comprises a trigger pulse shaping circuit, a negative pulse separation circuit, a positive pulse separation circuit, an ignition advance angle control circuit, a boosting circuit taking a boosting transformer and a switch power tube as cores, and an ignition discharging circuit, and is characterized in that: the ignition advance angle control circuit takes a singlechip processor as a core; and the singlechip processor controls the boosting circuit in a pulse width modulation (PWM) mode. The ignition advance angle control circuit takes a singlechip as a control core, and the ignition advance angle of an engine is subjected to accurate curve control through the quick operation and control functions of the singlechip, so that the engine works in an optimal state; and the PWM control mode is adopted, so that constant high power is output when the boosting transformer is started, and the rise rate of charging voltage of an ignition capacitor is improved.

The invention discloses a low-cost weak radionuclide detecting method. Compared with an existing method, according to the method, firstly, a plastic scintillation spectrometer and a lanthanum bromide spectrometer form a double-coincidence detecting array structure, detecting efficiency, energy resolution, application cost and other factors are comprehensively considered, a lanthanum bromide detector is adopted as a main detector, a plastic detector is adopted as a coincidence detector, and an anticoincidence and coincidence measurement method is adopted for reducing the environmental background and increasing the system peak-to-compton ratio; secondly, front-end fast electronic circuit development and a subsequent digital processing algorithm are carried out on an electronic circuit of nuclear signal processing, pulse forming, base line restoration, overlapped pulse separation and the like are included, noise interference is reduced, and the energy resolution is increased; finally, a plastic scintillator is directly adopted as a shielding material of the main detector lanthanum bromide, therefore, the system weight can be reduced, and detecting efficiency can be improved.

The invention relates to a high-energy ultrashort pulse fiber laser which comprises a seed pulse oscillator (1), a chirped pulse stretcher (2), a fiber pre-amplifier (3), a pulse separation device (4) and a nonlinear amplification compressor (5), wherein a pulse output by the seed pulse oscillator (1) is stretched through the chirped pulse stretcher (2) and then is pre-amplified through the fiber pre-amplifier (3), then a separated pulse is generated through the pulse separation device (4), and is injected into the nonlinear amplification compressor (5) to generate a high-energy separated ultrashort pulse, the high-energy separated ultrashort pulse enters the pulse separation device (4) again for beam combination, and then high-energy ultrashort pulse laser is output. The high-energy ultrashort pulse fiber laser disclosed by the invention realizes the organic combination of chirped pulse amplification and non-linear pulse compression by adopting a pulse separation method, thereby effectively preventing the excessive high-order chromatic dispersion from being introduced in a pulse stretching process and effectively controlling the non-linear effect in a nonlinear amplification process. According to the high-energy ultrashort pulse fiber laser disclosed by the invention, a method is simple and easily operated by controlling pulse separation through an optical crystal quantity; the high-energy ultrashort pulse fiber laser can be suitable for the laser amplification of a plurality of wave bands.

A method of performing high repetition rate laser time domain imaging employs as fluoroprobes semiconductor nanocrystals having a fluorescence lifetime less than the laser pulse separation, typically less than 5 ns. The nanocrystals of the invention have a core/shell structure and may be surface treated to increase radiative decay. CdSe/Zns nanocrystals are particularly suitable.

The invention discloses an HCCI diesel engine fuel oil mist spray testing device and belongs to the field of electrical control. The HCCI diesel engine fuel oil mist spray testing device comprises a high-pressure fuel oil injection system, a circuit control system, a nitrogen supply system and a visual engine. The high-pressure electronic control fuel oil injection system has the advantages of being high in injection pressure, capable of adding a fluorescent agent easily and the like, and meanwhile multiple-pulse fuel oil injection can be achieved. According to the fuel oil injection system, the fluorescent agent can be added easily; moreover, the injection pressure is high, the multiple-pulse fuel oil injection can be achieved, and the circuit control system can synthesize multiple-pulsefuel oil injection control signals; and the pulse width, pulse separation and frequency, pulse injection advance angles and main injection are flexible and adjustable, and an excimer laser, a CCD andan ICCD can be coordinately controlled to achieve synchronous working with fuel oil injection.

The invention discloses a train-braking impulse control method. The train-braking impulse control method relates to a train pipe arranged on a train, a controller, a pipe communicated with the train pipe, a pressure sensor arranged on the pipe, an AD convertor, a processor, an electromagnetic valve arranged at the back portion of an air discharging opening of the pipe and a driving circuit of the electromagnetic valve; the signal output end of the pressure sensor, the AD convertor, the processor, the electromagnetic valve of the driving circuit are sequentially and electrically connected; the controller is electrically connected with the processor. The train-braking impulse control method has the advantages that the pulse separation and the pulse width can be calculated according to variation of pipe pressure, and the train can reduce pressure at the stable rate.

The invention provides a portable device and a measurement method for measuring the sound absorption coefficient of a material based on short sound tube and superimposed pulse extraction. According tothe propagation characteristics of a plane wave in a sound tube, direct and incident waves superimposed in the short sound tube are extracted through operations such as proper shift addition, and thevertical incident sound absorption coefficient of the material is calculated. The physical meaning is clear and the operation is simple. The length of the tube used by the method is short, which avoids the problem of frequency limitation of a transfer function method and the problem of sound attenuation of a pulse separation method. The convenience of the experimental operation is improved, and conditions are provided for the portable pulse method.