124results about How to "High pulse energy" patented technology

An eye-safe atmospheric aerosol lidar featuring high transmit pulse energy to generate strong backscatter from long ranges in a single pulse together with an optically efficient receiver is disclosed. The transmitter employs a gas cell and non-focused laser beam geometry to convert short wavelength laser light to substantially safer and longer wavelength light by stimulated Raman scattering. The longer wavelength light is substantially safer than the shorter wavelength light thereby allowing the safe transmission of high energy pulses. The transmitter also features a diode injection seed and a beam expander which are effective to reduce the divergence of the long wavelength light below the field-of-view of the receiver. The receiver employs a telescope, collimating lens, interference filter, focusing lens, avalanche photodiode detector, amplifier and analog to digital converter. The transmit beam and receiver field of view are coaxial. Initial results demonstrate the ability of such technology to elucidate the structure of the atmosphere with high temporal and spatial resolution.

A method and apparatus use a photonic-crystal fiber having a very large core while maintaining a single transverse mode. In some fiber lasers and amplifiers having large cores problems exist related to energy being generated at multiple-modes (i.e., polygamy), and of mode hopping (i.e., promiscuity) due to limited control of energy levels and fluctuations. The problems of multiple-modes and mode hopping result from the use of large-diameter waveguides, and are addressed by the invention. This is especially true in lasers using large amounts of energy (i.e., lasers in the one-megawatt or more range). By using multiple small waveguides in parallel, large amounts of energy can be passed through a laser, but with better control such that the aforementioned problems can be reduced. An additional advantage is that the polarization of the light can be maintained better than by using a single fiber core.

An apparatus for performing laser-induced breakdown spectroscopy comprises a handheld unit with a pump laser and a controller. A combination of a solid laser medium and a Q-switch receive a laser beam from said pump laser. Focusing optics focus laser pulses from said combination to a focal spot at a sample. Light collection optics collect light from plasma induced of sample material by focused laser pulses. A spectrometer receives collected light and produces information describing its spectral distribution. A power source delivers electric power to other parts of the apparatus. The pump laser, combination, focusing optics, light collection optics, spectrometer and power source are parts of said handheld unit.

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 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.

An electro-adhesive tissue manipulator capable of manipulating tissue with a single conducting element is provided. The manipulator includes a conducting element, an electrical means and a control means capable of generating a first and a second pulse on demand. The first pulse generates an adhesive state between the conducting element and the tissue layer strong enough to manipulate the tissue layer. The second pulse, which has higher pulse energy than the first pulse, generates a non-adhesive state to detach the adhered tissue layer from the conducting element. The electro-adhesive device could be combined with a medical instrument to enhance the capabilities of the medical instrument so that it can manipulate tissue. The advantage of the present invention, in contrast to mechanical tools, is that tissue can be manipulated with a single tip of a conducting element, without folding and piercing of the tissue, thus avoiding damage to the tissue.

The invention discloses a laser processing method for a steel sieve tube slit. One end point of one long edge of the slit is used an initial point. The method comprises the following steps of: perforating a hole at the initial point of a cut by using pulse laser, and then finishing the cutting of the whole slit from the initial point by using continuous laser. During cutting, oxygen is used as an auxiliary gas, the metal at a cutting point is further heated by using reaction heat released by the reaction of the oxygen and the molten iron at the cutting point, meanwhile the molten iron is changed into ferroferric oxide with good liquidity by using chemical reaction, and the ferroferric oxide is blown away the cutting point by using airflow so as to ensure continuous cutting. The processing method solves the problems of irregular slit shape, slag adhesion at the cut and oblique blowing trace in the conventional laser cut sieve tube slit.

The invention discloses a particle image speed measuring device, method and system. The device comprises a laser unit for emitting the laser to a to-be-measured region; an acquisition unit for acquiring the particle image of the to-be-measured region; a control unit electrically connected with the laser unit and the acquisition unit to control the movement and/or state of the laser unit and the acquisition unit, wherein the laser unit emits at least two beams of laser, and the light emitting time sequence between the laser beams satisfies the incremental or decreasing relation; the acquisitionunit at least comprises two acquisition channels, and the acquisition time of each acquisition channel meets the incremental or decreasing relation, and corresponds to the light emitting time sequence of each beam in the laser unit in sequence. The device and the method overcome the contradiction that the light emitting frequency and the pulse energy of a single laser are difficult to improve atthe same time, the problem of high-speed photography is solved, and the resolution of the measurement system is greatly improved.

The invention relates to an internal combustion engine with a laser ignition device (1), Q-switched, pumped solid-state laser with a pulsed pumped light source (30), a solid laser crystal (2), enclosed in a resonator, a Q-switch (4), for increasing the power density, at least one output mirror (6) and a focussing device (7), by means of which the laser beam (26) may be focussed in a combustion chamber.

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.

Embodiments of the subject invention relate to a method and apparatus for performing measurements using multiphoton or second harmonic generation (SHG) scattered radiation from a sample including a turbid (scattering) medium includes providing a beam of laser pulses from a laser source having high pulse energies and a repetition rate; splitting the beam of laser pulses into two or more partial beams and focussing and overlaying the partial beams on a sample including the turbid medium; and detecting multiphoton and second harmonic radiation scattered from the sample.

The invention discloses an all-fiber structural laser system capable of generating high-energy wave-free split rectangular pulse, which aims to solve the technical problems that the current erbium-doped fiber laser has low pulse energy and poor stability and is difficult to realize rectangular pulse output. The all-fiber structural laser system comprises two wavelength division multiplexers, an erbium-doped fiber, a first polarization controller, a polarization dependent isolator, a second polarization controller and an output coupler connected in turn through an intra-cavity single mode fiber, wherein the input ends of the two wavelength division multiplexers are provided with pumping light sources. The length of the erbium-doped fiber is 10 to 20 meters, the total length of the single mode fiber is 5 to 10 meters, and the whole intra-cavity net dispersion is kept in a large positive value. The all-fiber structural laser system has the advantages of simple structure, low price, good stability and the like on application; and compared with a solid laser for generating high-energy rectangular pulse, the all-fiber structural laser system has the advantages of high pumping efficiency, adjustment convenience, good pulse quality and the like, and is easy for fiber coupling.

The invention relates to a micro-pulse laser radar light source with high pulse energy. The light source is formed by an oscillator stage and an amplifier stage; and the light path of the amplifier stage and the light path of the oscillator stage are in a coaxial mode. At the oscillator stage, a dual-path Q switch is used for compensating thermal depolarization loss of a laser; dual-path outputs are amplified respectively by the independent amplifier stage and then are combined, thereby realizing functions of thermal depolarization compensation and energy amplification. At the oscillator stage, a holophote, a laser crystal rod, two dielectric film polarizers, two Pockels boxes, and two output coupling mirrors are successively arranged on the light path; the two dielectric film polarizers are arranged at a brewster angle, incident surfaces of other elements are parallel to each other; and two end surfaces of the laser crystal rod are parallel to each other. According to the invention, losses of output energy by thermal depolarization can be compensated and the output energy can be amplified further; compared with the prior art, the conversion efficiency, the pulse energy, and the light beam quality of the light source are substantially improved; and the detection distance and detection precision of the micro-pulse laser radar are enhanced.

A Raman shifter is provided with improved optical efficiency and robustness, particularly for high power applications. In one embodiment, a source system (100) includes a source pump laser (102) and a seed laser (104). Beams from the pump laser (102) and seed laser (104) combine for transmission into a Raman cell (112). Folding optics define a multi-pass pathway through the Raman cell (112). Such folding optics may include an internal reflectance element. An entry window into the Raman cell, an exit window from the Raman cell, and the internal reflectance elements include surfaces disposed at a Brewster angle relative to the incident beam. The Raman cell medium is circulated in a direction transverse to the beam pathways through the cell. In this manner, improved optical efficiency and robustness is achieved as well as improved performance over a significant wavelength band.

A laser roughening machine with laser-gathering head array for metal surface, especially the surface of roller, is disclosed. The laser beam from laser device is amplified and then splitted into multiple beams, which are transmitted via relative optical fibres to the laser-gathering heads arranged by the form of rectangular, parallelogram or linear array on a small moving platform fixed the rotation shaft of numerally controlled machine-tool. After the roller to be roughened is fixed to the machine-tool and then rotating, the laser beams from said array scan on the surface of roller to generate pit matrix. Its advantages are short period and high uniformity of pit matrix.

The invention discloses a preparation method and application of an orthorhombic-phase two-dimensional layered SiP single crystal and a film. The method comprises the following steps that 1, Si, P and Sn are weighed, Sn serves as a metal fluxing agent, then the three raw materials are put in a quartz tube, and after the quartz tube is vacuumized, sintering is conducted for sealing the quartz tube; 2, the quartz tube is put in a heating furnace, a stage temperature rise program is adopted, and Si and P are in a sufficient combination reaction; 3, after o-SiP nucleates and grows, the quartz tube is taken out of a hearth and inverted, and an o-SiP single crystal and the metal fluxing agent Sn are separated; 4, the quartz tube is opened, the material block is taken out, the fluxing agent Sn adhering to the surface of o-SiP is removed, the material block is cleaned up, and a flaky o-SiP crystal is obtained; 5, the o-SiP crystal is immersed in an NaoH solution, sediment is extracted out after ultrasonic treatment, and the sediment is cleaned to obtain the orthorhombic-phase two-dimensional layered SiP single-crystal nano-film with a large size and high quality. The film can be applied to a saturable absorber for modulation of lasers and can be used for passive mode locking of an ultrashort pulse laser and manufacturing of photoelectronic devices or radiation detectors or solar cells.