594 results about "Picosecond" patented technology

Powerful nanosecond-range lasers using low repetition rate pulsed laser deposition produce numerous macroscopic size particles and droplets, which embed in thin film coatings. This problem has been addressed by lowering the pulse energy, keeping the laser intensity optional for evaporation, so that significant numbers of the macroscopic particles and droplets are no longer present in the evaporated plume. The result is deposition of evaporated plume on a substrate to form thin film of very high surface quality. Preferably, the laser pulses have a repetition rate to produce a continuous flow of evaporated material at the substrate. Pulse-range is typically picosecond and femtosecond and repetition rate kilohertz to hundreds of megahertz. The process may be carried out in the presence of a buffer gas, which may be inert or reactive, and the increased vapour density and therefore the collision frequency between evaporated atoms leads to the formation of nanostructured materials of increasing interest, because of their peculiar structural, electronic and mechanical properties. One of these is carbon nanotubes, which is a new form of carbon belonging to the fullerene (C60) family. Carbon nanotubes are seamless, single or multishell co-axial cylindrical tubules with or without dome caps at the extremities. Typically diameters range from 1 nm to 50 nm with a length >1 mum. The electronic structure may be either metallic or semiconducting without any change in the chemical bonding or adding of dopant. In addition, the materials have application to a wide range of established thin film applications.

Various embodiments of a system described herein relate to micromachining materials using ultrashort visible laser pulses. The ultrashort laser pulses may be green and have a wavelength between about 500 to 550 nanometers in some embodiments. Additionally, the pulses may have a pulse duration of less than one picosecond in certain embodiments.

Systems and methods are provided for scribing wafers with short laser pulses so as to reduce the ablation threshold of target material. In a stack of material layers, a minimum laser ablation threshold based on laser pulse width is determined for each of the layers. The highest of the minimum laser ablation thresholds is selected and a beam of one or more laser pulses is generated having a fluence in a range between the selected laser ablation threshold and approximately ten times the selected laser ablation threshold. In one embodiment, a laser pulse width in a range of approximately 0.1 picosecond to approximately 1000 picoseconds is used. In addition, or in other embodiments, a high pulse repetition frequency is selected to increase the scribing speed. In one embodiment, the pulse repetition frequency is in a range between approximately 100 kHz and approximately 100 MHz.

A novel method for high power optical amplification of ultrashort pulses in IR wavelength range (0.7-20 Ãm) is disclosed. The method is based on the optical parametric chirp pulse amplification (OPCPA) technique where a picosecond or nanosecond mode locked laser system synchronized to a signal laser oscillator is used as a pump source or alternatively the pump pulse is created from the signal pulse by using certain types of optical nonlinear processes described later in the document. This significantly increases stability, extraction efficiency and bandwidth of the amplified signal pulse. Further, we disclose five new practical methods of shaping the temporal and spatial profiles of the signal and pump pulses in the OPCPA interaction which significantly increases its efficiency. In the first, passive preshaping of the pump pulses has been made by a three wave mixing process separate from the one occurring in the OPCPA. In the second, passive pre-shaping of the pump pulses has been made by spectral filtering in the pump mode-locked laser or in its amplifier. In the third, the temporal shape of the signal pulse optimized for OPCPA interaction has been actively processed by using an acousto-optic programmable dispersive filter (Dazzler) or liquid crystal light modulators. In the fourth alternative method, the signal pulse intensity envelope is optimized by using passive spectral filtering. Finally, we disclose a method of using pump pulses which interact with the seed pulses with different time delays and different angular orientations allowing the amplification bandwidth to be increased. In addition we describe a new technique for high power IR optical beam delivery systems based on the microstructure fibres made of silica, fluoride or chalcogenide glasses as well as ceramics. Also we disclose a new optical system for achieving phase matching geometries in the optical parametric interactions based on diffractive optics. All novel methods of the ultrashort optical pulse amplification described in this disclosure can be easily generalized to other wavelength ranges.

A circuit card stripline Fast Faraday cup quantitatively measures the picosecond time structure of a charged particle beam. The stripline configuration maintains signal integrity, and stitching of the stripline increases the bandwidth. A calibration procedure ensures the measurement of the absolute charge and time structure of the charged particle beam.

A laser-based method and apparatus for corneal surgery. The present invention is intended to be applied primarily to ablate organic materials, and human cornea in particular. The invention uses a laser source which has the characteristics of providing a shallow ablation depth (0.2 microns or less per laser pulse), and a low ablation energy density threshold (less than or equal to about 10 mJ/cm.sup.2), to achieve optically smooth ablated corneal surfaces. The preferred laser includes a laser emitting approximately 100-50,000 laser pulses per second, with a wavelength of about 198-300 nm and a pulse duration of about 1-5,000 picoseconds. Each laser pulse is directed by a highly controllable laser scanning system. Described is a method of distributing laser pulses and the energy deposited on a target surface such that surface roughness is controlled within a specific range. Included is a laser beam intensity monitor and a beam intensity adjustment means, such that constant energy level is maintained throughout an operation. Eye movement during an operation is corrected for by a corresponding compensation in the location of the surgical beam. Beam operation is terminated if the laser parameters or the eye positioning is outside of a predetermined tolerable range. The surgical system can be used to perform surgical procedures including removal of corneal scar, making incisions, cornea transplants, and to correct myopia, hyperopia, astigmatism, and other corneal surface profile defects.

A latch circuit having three latch stages generates a majority output value from the stages, senses when the latch stage outputs are not all equal, and feeds the majority output value back to inputs of the latch stages to reload the latch stages. The latch circuit uses a not-equal gate whose output is an error signal that can be monitored to determine when a single-event upset has occurred. A master stage is controlled by a first multiplexer which receives one system clock signal, while a slave stage is controlled by a second multiplexer which receives another system clock signal, and the latch stage outputs are connected to respective inputs of the not-equal gate, whose output is connected to second inputs of the multiplexers. The latch circuit is part of a latch control system, and reloading of the latch stages takes less than one cycle of the system clock (less than 500 picoseconds).

The present invention relates to methods and systems for dynamically controlled laser amplifier configuration for composite cutting includes the steps of generating an initial wavelength-swept-with-time optical pulse in an optical pulse generator, amplifying the initial optical pulse, compressing the amplified optical pulse to a duration of less than 10 picoseconds and applying the compressed optical pulse on the composite with an ablating energy density, to controllably remove a slice of material from the composite.

A method of using picosecond scan camera to simultaneously obtain fluorescent light spectrum and fluorescent lifetime of sample includes focusing blue violet light emitted by laser on sample by objective to excite sample single photon, collecting fluorescent from sample then splitting it and focusing it to be image on photoelectric cathode of picosecond scan camera, setting dispersion direction of fluorescent to be the same as slit direction of said camera but to be vertical to scan direction in order to measure out fluorescent lifetime of different light spectrum simultaneously under coaction of scan circuit and image intensifier deflection system.

The invention is a method and apparatus for creating a color and optical density selectable visible mark on an anodized aluminum specimen. The method includes providing a laser marking system having a laser, laser optics and a controller operatively connected to said laser to control laser pulse parameters and a controller with stored laser pulse parameters, selecting the stored laser pulse parameters associated with the desired color and optical density, directing the laser marking system to produce laser pulses having laser pulse parameters associated with the desired color and optical density including temporal pulse widths greater than about 1 and less than about 1000 picoseconds to impinge upon said anodized aluminum.

The present invention provides a one-step process for producing and depositing size-selected nanoparticles onto a substrate surface using ultrafast pulsed laser ablation of solid target materials. The system includes a pulsed laser with a pulse duration ranging from a few femtoseconds to a few tens of picoseconds, an optical setup for processing the laser beam such that the beam is focused onto the target surface with an appropriate average energy density and an appropriate energy density distribution, and a vacuum chamber in which the target and the substrate are installed and the background gases and their pressures are appropriately adjusted.

In the present invention, a surface 7 of a glass substrate 1 is irradiated with a laser beam 2 to thereby form a V-shaped groove 6. At that time, the laser beam 2 is condensed outside and above the glass substrate 1. The distance between a beam-condensing point 4 of the laser beam 2 and the surface 7 of the glass substrate 1 is changed to thereby make it possible to change the angle between opposite side surfaces of the V-shaped groove. The angle is in a range of from 30 degrees to 120 degrees. Further, the laser beam used in the present invention is pulsed light, preferably with a pulse width not larger than 10 picoseconds.

The present disclosure concerns a means to use at least a form of electromagnetic excitation or light-matter interaction, including solar or laser energy to generate localized conditions that enable initiation and spatial and temporal control of catalysis, chemical reactions, deposition, synthesis, photocatalysis, electrocatalysis and catalytic processes. Initiation and spatial and temporal control may be obtained by restricting and directing the electromagnetic excitation or light-matter interactions to specific objects or features embedded or located in or on a host matrix material or substrate. In some implementations this provides a means to use electromagnetic excitation to initiate and control chemical synthesis or reactions without entirely or partially heating any of or all of the reaction chamber, reactor mass, reaction precursors and products, or reactor substrate. It may further provide for the use of temperature sensitive elements or substrates. The method of use could include initiation and control of light-matter interactions addressed at optical and other frequencies to generate controlled localized thermal conditions. A further implementation concerns a means to employ electromagnetic excitation or light-matter interactions to generate localized thermal conditions to initiate or control or cause the combination, separation, reformation or reclamation of a gas, a combination of gasses, a material or a combination of materials in the form of a gas, plasma, solid or liquid. The method of use disclosed could provide a means to initiate and control chemical reactions for the generation, use, transfer and output of controlled localized thermal heat or energy. The method of use disclosed could provide a means to realize and control local thermal conditions down to or below the length scale of a single nanometer and down to or below the timescale of a single picosecond. In some implementations surface plasmon excitations may be used to realize and control local thermal conditions down to or below the length scale of a single nanometer and down to or below the timescale of a single picosecond.

The invention is a method and apparatus for laser marking a stainless steel specimen with commercially desirable marks. The method includes providing a laser processing system having a laser, and laser optics and a controller with pre-determined laser pulse parameters, selecting the pre-determined laser pulse parameters associated with the desired mark, and directing the laser marking system to produce laser pulses having laser pulse parameters associated with the desired marks including temporal pulse widths greater than about 1 and less than about 1000 picoseconds.

A method and system for laser ablating a target material in an ambient atmosphere are disclosed. The method includes generating one or more laser pulses, each of the laser pulses having a pulse width of 1 picosecond (ps) or less and a pulse energy of 50 micro joules (μJ) or more. The laser pulses are directed towards the target material such that the laser pulses interact with a gas to form a plasma. The plasma removes a portion of the target material by interaction of the plasma with the target material.

The invention discloses a laser capable of simultaneously outputting nanosecond pulses and pico-second pulses. The laser comprises a signal source, a signal isolation system and an amplifier. According to the invention, with an electric light control technology of combining an extra-cavity Pockels cell and intra-cavity Pockels cell, a regenerative amplification process is realized in case of signal light importing so as to obtain high-energy pico-second laser output, and cavity empty process is also realized in case of no signal light importing so as to obtain nanosecond pulse output; and thefree combination of the two processes can be realized according to practical application demand, and as a result, free combination of numbers of the nanosecond pulses and the pico-second pulses in a single laser is realized and is output in an alternative way. The laser provided by the invention has an important application in high-precision high-efficiency fine processing field, as well as basicresearch fields such as plasma excitation, excited state control, chemical reaction control, special radiation excitation and the like.

The invention is a method and apparatus for laser marking a stainless steel specimen with commercially desirable marks. The method includes providing a laser processing system having a laser, laser optics and a controller with pre-determined laser pulse parameters, selecting the pre-determined laser pulse parameters associated with the desired mark, and directing the laser marking system to produce laser pulses having laser pulse parameters associated with the desired marks including temporal pulse widths greater than about 1 and less than about 1000 picoseconds.