33results about How to "Short pulse" patented technology

A method for repairing process-related damage of a dielectric film includes: (i) adsorbing a first gas containing silicon on a surface of the damaged dielectric film without depositing a film in the absence of reactive species, (ii) adsorbing a second gas containing silicon on a surface of the dielectric film, followed by applying reactive species to the surface of the dielectric film, to form a monolayer film thereon, and (iii) repeating step (ii). The duration of exposing the surface to the first gas in step (i) is longer than the duration of exposing the surface to the second gas in step (ii).

A method of generating supercontinuum optical radiation, the method comprising: (a) providing an optical waveguide (22), said optical waveguide exhibiting a dispersion characteristic of guided optical radiation, said dispersion characteristic comprising: (i) a first dispersion parameter (β21) at a first wavelength (λ1), (ii) a second dispersion parameter (β22) at a second shorter wavelengths (λ2), and (iii) a zero-dispersion parameter at a wavelength in between said first and said second shorter wavelengths; said optical waveguide further comprising at least one entrance for receiving optical radiation, and at least one exit for emitting guided optical radiation; (b) applying at least two laser radiation of said first (25) wavelength, (λ1) at a first power (P1) and applying laser radiation of said second (26) shorter wavelength (λ2) at a second power (P2) into said optical waveguide, said laser radiations at least partially overlapping between said at least one entrance and said at least one exit of said optical waveguide; and (c) phase-matching said applied laser radiations by adjusting said first and second powers; a supercontinuum optical radiation source; and use thereof.

The invention discloses a negative dispersion pulse widening optical fiber amplifying device, which comprises a mode-locked laser, a negative dispersion unit, a primary amplifying unit, a secondary amplifying unit and an output unit, wherein the mode-locked laser generates seed light pulse; the negative dispersion unit is arranged at the emergent side of the seed light pulse of the mode-locked laser to widen the seed light pulse and enable the seed light pulse to have negative chirp; the primary amplifying unit receives the seed light pulse with the negative chirp, which is output by the negative dispersion unit, carries out primary amplification, and further carries out positive dispersion compensation on the negative chirp in the seed light pulse to shorten the seed light pulse; the secondary amplifying unit receives the seed light pulse output by the primary amplifying unit, carries out secondary amplification, and further carries out positive dispersion compensation on the negative chirp in the seed light pulse to shorten the seed light pulse; and the output unit is connected with the secondary amplifying unit and outputs the amplified seed light pulse. The invention makes the pulse of the output end of the optical fiber amplifier shortest via the negative dispersion widening, simplifies the system, reduces the loss, increases the pulse energy after the amplifier, and effectively reduces the cost.

The present invention relates to a method for identifying an entity comprising placing an internal tag within the entity and placing an external tag proximate the entity wherein the internal tag and external tag are coupled.

The present invention contemplates a simplified laser oscillator-amplifier system for deep UV generation. The simplified system employs same type of gain media in both the oscillator and the amplifier and utilizes a single pump pulse split to pump both the oscillator and the amplifier. A short cavity oscillator is operated near lasing threshold to produce a seed pulse with a narrow spectral bandwidth and long pulse duration. A short cavity amplifier is Q-switched to amplify the seed pulse to produce a single short pulse with good energy extraction efficiency. The amplifier is simply a short cavity, Q-switched laser. Short pulse is obtained with short cavity length and high gain of the amplifier. Consequently, the simplified laser oscillator-amplifier system can accommodate a long pump pulse to produce a nanosecond pulse suitable for deep UV laser generation.

A thermal inkjet printhead with a heater element disposed in each of the bubble forming chambers wherein, the heater element has a protective surface coating that is less than 0.1 μm thick while still being capable of ejecting more than 1 billion drops without failure. Removing most or all of the protective coatings from the heater reduces or eliminates the thermal insulation between the heater and the ink. Nucleating a bubble in the ink chamber requires a much shorter pulse of less energy thereby improving printhead efficiency.

The invention discloses an independent tuning microwave electron gun with external cathode which is composed of an external negative pole, namely, dipolar gun, a microwave cavity, a tuning mechanism, a first cavity input waveguide, a second cavity input waveguide and a cooling water pipe; the external negative pole and the microwave cavity are connected by Kovar flange argon-arc welding, the tuning mechanism and the microwave cavity are connected by braze welding in a hydrogen furnace, the first cavity input waveguide and the second cavity input waveguide are connected with the microwave cavity by braze welding, but the first cavity input waveguide and the second cavity input waveguide are connected at different longitudinal positions of the microwave cavity with the angles being mutually perpendicular, and then connected with a waveguide transmission line fed with microwave power respectively. The invention is designed to solve manufacture technique, so that the electron gun has simple structure and electron beam is excellent in performance, thus providing a novel electron beam source device for compact type free electron laser and electron linear accelerator.

The invention relates to an all-optical fiber type device for detecting and treating superficial cancer cells. The all-optical fiber type device comprises three parts, i.e., a removable optical fiber type laser generator, a detecting and treating device and a record and analysis system, wherein the three parts are connected by optical fibers, the detecting and treating device is in a round guide rail shape, the round guide rail shape is fixedly provided with a terahertz generating module and a terahertz detecting module, and a detected human body is positioned in the round guide rail shape; laser light generated by the optical fiber type laser generator can be conducted by the optical fibers, a part of light can reach the terahertz generating module through a delay line, the other part of light can reach the terahertz detecting module through an attenuator and a polarizer, and the optical lengths of two light beams are enabled to be equal by regulating the delay line; the terahertz generating module is used for outputting and emitting parallel light, and the parallel light are used for irradiating the detected human body; terahertz waves reflected back by the human body can enter the terahertz detecting module; the terahertz waves can be output to the record and analysis system by the terahertz detecting module. According to the all-optical fiber type device disclosed by the invention, spectrum analysis on organ tissues of the human body can be carried out through a terahertz technology, and the all-optical fiber type device is in an all-optical fiber type and is convenient to move.

The invention discloses a 2.79 mu m Q-switched erbium laser dental instrument. The 2.79 mu m Q-switched erbium laser dental instrument comprises a laser power supply, a laser component, a laser water cooling system, a light guide output system, a gas and water spraying system and a central control system; the laser power supply is used for providing energy to the laser component; the laser component consists of a total-reflection chamber piece, a polarizer, a Q-switched crystal, a xenon lamp, a laser rod, a light condensing chamber, a wave plate and an output chamber piece; the laser water cooling system is used for cooling the laser rod and the xenon lamp in the laser component; the light guide output system is used for conducting laser, and is convenient to operate and use; the gas and water spraying system is used for spraying a mixture of gas and water to a laser acted tooth tissue, and has the effects of reducing the temperature of the tissue and participating laser treatment; the central control system is used for controlling the parameters of the laser power supply, the laser water cooling system and the gas and water spraying system to ensure the coordination work among the subsystems. The 2.79 mu m Q-switched erbium laser dental instrument has pulse Q-switched laser which has short pulse width and high peak power and acts the tooth tissue to improve ablation precision; meanwhile, the thermal damage to peripheral tissues also can be effectively reduced; the pain of a patient can be reduced effectively.

A super-strong chirped laser pulse step-by-step compression device comprises a light beam smoothing and initial pre-compression module composed of prism peer-to-peer negative dispersion elements, a pulse main compression module composed of a grating compressor and the like, and a final compression module composed of a space-time focusing process and (or) a self-compression process in a transparentmedium sheet. By utilizing the smoothing effect of the pre-compression module on the spatial intensity modulation of the incident laser, the modulation of the spatial intensity of the laser is reduced, and the damage of the spatial modulation of the laser intensity to the incident grating and the emergent grating is reduced, so that the energy of the incident laser can be improved, and stronger laser output can be obtained at a single stage. And in the pulse self-compression process of the final compression module, the spectrum can be further broadened, and the laser pulse can be compressed to obtain shorter laser pulse output.

The invention discloses a medical 2.79-micrometer electro-optical Q-switched Cr, Er: YSGG (Erbium, Chromium: Yttrium-Scandium-Gallium-Garnet) laser device which comprises a total reflection cavity sheet, a Q-switched crystal, a polarizer, a xenon lamp, a laser rod, a condensation cavity, a wave sheet, an output cavity sheet, a laser power supply and a laser water cooling system, wherein the laser rod and the xenon lamp are mounted in parallel in the condensation cavity, and connected with the water cooling system; the water cooling system cools the condensation cavity, and the laser rod and the xenon lamp in the condensation cavity; the laser power supply provides electric energy for the xenon lamp, and has a function of coordination, such as controlling the xenon lamp, an electro-optical Q switch, and the water cooling system; a Q-switched power supply in the power supply controls the opening time of the electro-optical Q switch, provides Q-switched high voltage, and is connected with two electrodes of the Q-switched crystal; the two electrodes are positioned on the two sides of the Q-switched crystal, and clung to the surface of a Y-Z plane of the Q-switched crystal, and are parallel to a laser oscillation path; the electro-optical Q switch consists of the polarizer and the electro-optical Q-switched crystal; the Q-switched crystal is a lanthanum gallium silicate (LGS) crystal; the laser rod is a Cr, Er: YSGG laser crystal; and the wave sheet is a 1 / 4 wave sheet. The laser device has the characteristics of stable output power, and uniform light spot intensity distribution.

The invention provides a pre-chirp management femtosecond pulse laser coherent combination amplification device. The device comprises a femtosecond laser front-end module, a pre-chirp management module, a pulse beam splitter module, an optical fiber amplifier module, a pulse beam combiner module, a pulse compression module and a time delay adjustment module. The pre-chirp technology is adopted to increase the spectrum broadening amount, the coherent combination technology is adopted to increase the output average power, and two paths of coherent combination can output sub-50 femtosecond ultrashort pulses with the average power of five hundred watts; meanwhile, the expansibility is high, a plurality of rod-shaped photonic crystal gain optical fibers can be added in parallel on the basis of an existing system to further improve the output average power, and a pulse separation / synthesis unit in time can be added to improve the output pulse energy of the system.

The present invention provides a positive electron beam transmission system. The laser in the system is emitted from a laser source, enters a vacuum target chamber and is reflected by a plane mirror onto the reflection focusing mirror of an off-axis paraboloid; and the laser is focused at the position about 2mm far away from the top of a gas target assembly, a tantalum target is located behind the gas target assembly, and a sighting device is located behind the tantalum target. The beam transmission system comprises a vacuum pipeline, a solenoid coil, a dipolar magnet, a beam dustbin, the sighting device and another solenoid coil. The positive electrons and electrons enter the vacuum pipeline at the outside of the vacuum target chamber together and are focused by the solenoid coil, then negative electrons pass through the dipolar magnet and enter the beam dustbin, and the positive electrons pass through the sighting device and are focused by the solenoid coil behind the sighting device.

A continuous or a long-pulsed microwave oscillated from a microwave oscillator 1 is propagated in a waveguided tube 2 in which a given gas is charged. Subsequently, by irradiating a laser having a given intensity from a laser source 4 to the points, A and B in the tube 2, the given gas is partially made plasma. Just then, the microwave can not travel beyond the plasma-part of the given gas and reflects thereat. Accordingly, the microwave is divided at the plasma-part and thereby, a short-pulsed microwave can be obtained.

The invention relates to a device for a laser blocked-mode, especially for a pulsed laser, comprising a cavity resonator (20) which is defined by a first mirror (1) and a second mirror (8), and fitted with an amplifying active laser medium (5) for the amplification of a beam of laser radiation of a fundamental frequency (ω1) and a solid, non-linear optic means (10) comprising at least said second mirror (8) for reversible conversion of the radiation of the fundamental frequency (ω1) into radiation of a harmonic frequency (ω2) whereby said non-linear optic means (10) has a reflection factor which increases with the intensity of the radiation of a fundamental frequency. The invention is characterized in that said device also comprises a solid intensity limiter (4) in the cavity resonator (20), whereby the transmission factor of the laser radiation decreases with the intensity of said radiation. The invention also relates to a method for a laser blocked-mode, especially for a pulsed laser, using said device.

An adaptive bitrate streaming method streams audio video (AV) to a client using a multi content delivery network (CDN) approach. Each CDN stores versions of content that can be requested in a succession of consecutive files using HTTP requests. The method is based on use of an intermediate module between an AV player of the client and each CDN. For each file of a version requested by the AV player, the intermediate module requests a manifest file to each CDN and estimates a bitrate of each CDN using reception performances of the manifest files. Each file is requested by the intermediate module in a succession of segment groups according to a pattern including a predetermined number of segments. Each group includes one set of segments for each CDN, each set including segments to be requested to the CDN to which they correspond proportional to the bitrate of this CDN.

Disclosed is a device for, in combination with a stop having an aperture, generating charged particle beam pulses, an apparatus for inspecting a surface of a sample, and a method for inspecting a surface of a sample. The device includes a deflection unit which is arranged for positioning in or along a trajectory of a charged particle beam. The deflection unit is arranged for generating an electric field for deflecting said charged particle beam over the stop and across the aperture. The device also includes an electrical driving circuit for providing a periodic signal. The electrical driving circuit is connected to the manipulation unit via a photoconductive switch, wherein the photoconductive switch is arranged for: substantially insulating the deflection unit from the electrical driving circuit, and for conductively connecting the deflection unit to the electrical driving circuit only when said photoconductive switch is illuminated by a light beam.

The invention belongs to the technical field of femtosecond lasers, and discloses a large-energy-cavity-dumped Yb femtosecond laser which comprises a pumping source, an optical coupling system, a planar dichroic mirror, a Yb laser crystal, a first concave mirror, a second concave mirror, an output mirror, a first GTI mirror, a second GTI mirror, a third GTI mirror, a third concave mirror, a nonlinear medium, a fourth concave mirror, a TFP, an electro-optical modulator and a planar mirror. The cavity-dumped laser is based on a high-power Kerr lens mode-locked oscillator, starts mode locking without the help of an SESAM device prone to damage, and guarantees that mode-locked pulses in a cavity have the short pulse width and the high single pulse energy; and after the large-energy short-pulse-width pulse in the cavity is stably oscillated, the electro-optical modulator is used for changing a polarization state of laser, and the pulse laser larger than 0.5 mu J and smaller than 100 fs in pulse width can be effectively guided out and achieved in combination with the TFP.

The invention relates to an ultrasonic transmitting circuit for medical ultrasonic diagnosis. The transmitting circuit comprises a push-pull output module, a positive-negative-pressure regulating module and a power module, wherein the push-pull output module is used for producing exciting pulses of positive and negative pressures, and the positive-negative-pressure regulating module is used for regulating the positive and negative pressures of the push-pull output module, so that the exciting pulses of the positive and negative pressures produced by the push-pull output module are symmetrical. The power module is used for providing voltage for the transmitting circuit. The sound wave energy outwards propagated by the transmitting circuit is increased, so that sound waves are uniform, and echo quality is improved. In addition, the connecting time of NMOS and PMOS transistors is shortened and the exciting pulses are shortened by increasing connecting-charging currents of the NMOS and PMOS transistors of the push-pull output module, and accordingly the longitudinal resolution of ultrasonic images is improved.

A method for electrical discharge machining a work piece using rectangular processing pulses includes forming the rectangular processing pulses by discharging one or multiple discrete delay lines that comprise multiple storage elements. The storage elements are arranged as part of a feed line to a spark gap on a section of the feed line near the spark gap. The discrete delay lines are connected to a guide head by an electrode-side contact unit and are connected to the work piece by a work piece-side contact unit.

The invention discloses a backing material for ultrasonic detection probe and manufacturing method thereof, wherein the material comprises tungsten powder and soft thermoplastic resin, the percentage by volume of tungsten powder in the backing material is 32-95%, its preparing method comprises the steps of, (1) dissolving the soft thermoplastic resin into right amount of organic solvent, (2) charging tungsten powder into the solution, (3) stirring and heating the obtained colloidal solution so as to remove the organic solvent through evaporation, thus obtaining composite particles through resin deposition on the surface of the tungsten powder particles, (4) loading the composite particles into die assembly, then heating the resin to glass transition temperature and press forming with hydrostatic machine.

The invention discloses a spectrometer calibration spectral line generator and a generation method thereof. A high-repetition-frequency femtosecond fiber laser is adopted, the output power is high, the pulse is short, a super-continuum spectrum is directly generated in a photonic crystal fiber, and the system is simplified; another set of device required for generating an octave spectrum is omitted, so that the system is further simplified; the side mode rejection ratio after filtering of an ultra-stable cavity is high, the noise is low, and distinguishing in a spectrograph is facilitated; asthe light of different spectral bands is subjected to ultra-stable cavity filtering and frequency interval multiplication in different spectrum elimination intervals at the same time, calibration spectra of different bands and different frequency intervals can be obtained at the same time, the spectra can be clearly distinguished in the whole spectrograph detection interval, and the enough numberof calibration spectral lines are provided; and a spectrum flattening reflector is adopted, a common device of a grating and a spatial modulator is omitted, the reflector eliminates too high spectrumcomponents, space and cost are saved, and stability and operability of the system are also improved.

This document describes an adaptive bitrate streaming method allowing streaming an audio video (AV) content to a client device using a multi content delivery network (CDN) approach. Each CDN stores multiple versions of a content that can be requested in the form of a succession of consecutive files using HTTP requests. The method is based on a use of an intermediate module, called diversity module, between an AV player of the client device and each CDN of a plurality of CDN. For each file of a version of a content requested by the AV player, the diversity module requests a manifest file to each CDN and estimates a bitrate of each CDN using reception performances of the manifest files. Each file is requested by the diversity module in the form of a succession of groups of segments structured according to a pattern comprising a predetermined number of segments. Each group comprises one set of segments for each CDN, each set comprising a number of segments intended to be requested to the CDN to which they correspond proportional to the bitrate of this CDN.

A resonant DC-DC converter for generating high voltage MHz bi-polar DC pulses includes a left multi-level resonant rectifier bank [100] connected to a positive electrode [104] and coupled via capacitive isolation to a left RF amplifier terminal [128]; a right multi-level resonant rectifier bank [102] connected to a negative electrode [106] and coupled via capacitive isolation to a right RF amplifier terminal [130]. Each multi-level resonant rectifier bank comprises multiple resonant rectifier stages [112-122], where each stage comprises two capacitors for capacitively isolating the stage, an output capacitor, a MOSFET switch connected to an adjacent MOSFET switch of an adjacent stage, and a gating resonant circuit connected to the MOSFET switch, whereby MOSFET switches in the banks can be passively controlled by RF signals from a left RF amplifier and a right RF amplifier.

The invention discloses a negative dispersion pulse widening optical fiber amplifying device, which comprises a mode-locked laser, a negative dispersion unit, a primary amplifying unit, a secondary amplifying unit and an output unit, wherein the mode-locked laser generates seed light pulse; the negative dispersion unit is arranged at the emergent side of the seed light pulse of the mode-locked laser to widen the seed light pulse and enable the seed light pulse to have negative chirp; the primary amplifying unit receives the seed light pulse with the negative chirp, which is output by the negative dispersion unit, carries out primary amplification, and further carries out positive dispersion compensation on the negative chirp in the seed light pulse to shorten the seed light pulse; the secondary amplifying unit receives the seed light pulse output by the primary amplifying unit, carries out secondary amplification, and further carries out positive dispersion compensation on the negative chirp in the seed light pulse to shorten the seed light pulse; and the output unit is connected with the secondary amplifying unit and outputs the amplified seed light pulse. The invention makes thepulse of the output end of the optical fiber amplifier shortest via the negative dispersion widening, simplifies the system, reduces the loss, increases the pulse energy after the amplifier, and effectively reduces the cost.

The invention, which relates to the technical field of laser resistor trimming, discloses a method for precise resistor trimming on a flexible substrate by using ultrafast laser. Precise resistor trimming of a flexible circuit board is carried out by using ultrafast laser creatively; and the ultrafast laser material removing process is a cold treatment process, and only the material zone under theultrafast laser effect is removed but the surrounding material is not affected obviously. Meanwhile, the ultrafast laser has the short pulse. The resistor trimming by using the ultrafast laser has the following advantages: firstly, the resistor trimming precision is improved; secondly, the resistive material / structure is protected from being damaged; and thirdly, the thermal damage of the substrate is avoided. Moreover, since the existing flexible devices are made of flexible non-metallic materials that include glass or plastic materials and the like and have the thicknesses of more than tenor even tens of micrometers, the resistor trimming needs cold-processing ultrafast laser due to the high temperature sensitivity of the devices. Therefore, the method has broad application prospects.

The invention relates to a medium laser accelerator and a vertical cavity surface laser. An XYZ space rectangular coordinate system is defined. The medium laser accelerator comprises a vertical cavity surface laser, the vertical cavity surface laser comprising an active layer and an acceleration area arranged in front of the Z-axis direction of the active layer, the main extension plane of the active layer being parallel to the plane defined by the X axis and the Y axis, and the acceleration region being provided with an acceleration channel parallel to the X-axis direction; a reflecting mirror, arranged on a light path of the laser emitted by the vertical cavity surface laser and used for reflecting the laser emitted by the vertical cavity surface laser at a specific angle; and a saturable absorption mirror, having corresponding absorptivity for the laser with different light intensities reflected by the reflecting mirror, and can compress the pulse width of the laser and reflect the compressed laser back to the vertical cavity surface laser through the reflecting mirror. A higher accelerating electric field can be obtained in an accelerating area, and the accelerating gradient of the medium laser accelerator is improved.

The invention discloses a novel time hopping-pulse position keying and telemetering method, and belongs to the field of wireless measurement and control communication. The multiple access communication of a PPK (pulse position key) telemetering system can be realized by adopting a time hopping frequency-spreading technique; and a receiving end completes the multiuser detection in a matched filtering mode. The method disclosed by the invention is safe, secret, anti-jamming, and strong in anti-intercepting capacity, and has the multiple access communication capacity.