639 results about "Ultrashort pulse" patented technology

A modelocked linear fiber laser cavity with enhanced pulse-width control includes concatenated sections of both polarization-maintaining and non-polarization-maintaining fibers. Apodized fiber Bragg gratings and integrated fiber polarizers are included in the cavity to assist in linearly polarizing the output of the cavity. Very short pulses with a large optical bandwidth are obtained by matching the dispersion value of the fiber Bragg grating to the inverse of the dispersion of the intra-cavity fiber.

A system and method for generating an optical laser pulse train of constant ultrashort pulse duration and low timing jitter in a fiber ring laser system (resonator) while keeping the laser resonator resilient to environmental conditions like temperature, humidity and pressure. The laser resonator may be actively mode-locked with a periodic electrically driven modulation at a specific frequency that corresponds to the inverse of the transit time inside the resonator. The optical pulse train quality may be monitored in real time, and the frequency of the modulation may be dynamically tuned in real time to compensate for resonator length changes due to changes in the environmental conditions.

The present invention provides a method for slicing a single crystal, wherein the single crystal is sliced by irradiating a portion to be sliced with an ultra short pulse laser beam while supplying a gas containing gaseous molecules or radicals that react with atoms constituting the single crystal to become stable gaseous molecules in the vicinity of the portion under slicing. Thus, there is provided a method for slicing a single crystal by using a laser processing, in which a single crystal is processed while obtaining a good sliced surface and markedly reducing a slicing loss.

The invention discloses laser-array pore molding devices and a method. The steps of the invention includes that, firstly, pore diameter, pore distance and caliber parameter of a pore plate are set, and a processing file is produced, secondly, laser power, pulse width, pulse repetition frequency and pulse count are set, thirdly, the parameter of light beam location scanning is set, fourthly, work-pieces are located, a visual system is located, and vacuum negative pressure absorbs a probe guide plate, fifthly, pressure and flow capacity of opening assistant gas are set, the processing is started, finally, the pore diameter, the pore distance and the caliber parameter are measured after the finishing of the processing. The laser-array pore molding devices include an ultraviolet solid laser with high repetition rate and ultrashort pulse, a laser beam generator, a collimation beam-expanding device, a shutter, a light beam location scanning device, a CCD visual location system, an XYZ displacement working platform, and a vacuum negative pressure absorbing-sheet frame. The invention has the advantages that the disadvantages of low efficiency, easy damage of a 'punch', changeable pore diameter and the like which exit in the present mechanical punching manner are overcome, dynamic digital hologram is directly pressed on the surface of the material of noble metal commemorative coins, thereby ensuring the esthetics of the commemorative coins.

Systems, methods, circuits and/or devices for generating high repetition rate ultra-short pulses are described. As one of many examples, an optical pulse generating laser system is described that produces mode-locked optical pulses. The laser system incorporates an optical pulse generation device that includes two optical loops coupled via a beam splitter. In addition, the optical pulse generation device includes an optical gain medium that is associated with the first optical loop, and a saturable element that is disposed in either the first optical loop or the second optical loop. The saturable element is operable to modulate a group of optical pulses propagating in at least one of the first optical loop and the second optical loop to create a group of substantially regular modulated pulses.

A system and method for repairing a photomask (52) for use in a photolithography process is disclosed, the photomask (52), consisting of a substrate layer (38) and a chrome layer (36) over the substrate layer (38), having a defect (42) in the chrome layer (36), the method comprising: providing a pulsed laser source (1) for generating an ultra-short pulsed laser beam; providing optical elements for scanning, directing and focusing the pulsed laser beam at a desired target location; directing the pulsed laser beam through the substrate and focusing it on a target location located inside the substrate adjacent the defect (42) to write a diffractive optical element (34), thus changing the scattering properties of the substrate at the target location.

A multi-channeled measuring method for measuring a spectrum of a terahertz pulse includes the steps of a terahertz pulse generating step for generating a terahertz pulse by using an ultrashort pulsed pumping light, a white light generating step for generating a white light pulse by using an ultrashort pulsed probe light, a stretching step for stretching and chirping the white light pulse generated at the white light pulse generating step, an electro-optic modulating step for modulating the chirped white light pulse stretched and chirped at the stretching step in such a manner that the terahertz pulse and the chirped white light pulse irradiate into an electro-optic crystal synchronously, so that the chirped white light pulse is modulated by an electric field signal induced at the electro-optic crystal irradiated by the terahertz pulse, a multi-channeled spectral detecting step for detecting a spectrum of chirped white light pulse modulated at the electro-optic modulating step by a multi-channeled detector, an electric field signal analyzing step for analyzing an electric field of the terahertz pulse irradiated to the electro-optic crystal from the spectrum of the chirped white light pulse detected by the multi-channeled spectrum detecting step, and a Fourier transforming step for transforming the electric field signal analyzed by the electric field signal analyzing step into a frequency spectrum of the terahertz pulse.

The invention belongs to the field of laser processing, discloses an edge deletion method for thin-film solar cells, and concretely relates to a method for carrying out edge deletion on thin-film solar cells by using ultra-short pulse laser. The method disclosed by the invention is importantly characterized in that high-peak-power ultra-short pulse laser with an extremely high transparent conductive film absorption rate is introduced into an application of carrying out edge deletion on thin-film solar cells. Compared with laser power used by edge deletion implemented by using infrared nanosecond laser, the method can complete high-efficiency and high-quality laser edge deletion by using smaller average laser power; and glass is not easy to be damaged, the compatibility with different kinds of transparent conductive films is extremely strong, and the application cost is reduced.

The invention discloses a time pulse width measurement system for ultrashort pulses in different spatial positions and a measurement method thereof. The time pulse width measurement system for ultrashort pulses in different spatial positions comprises an ultrashort pulse light source, a beam splitter, a reflector, an optical delay platform, a nonlinear medium, a slit, a nonlinear sum frequency crystal and a precise detector. The time pulse width measurement system utilizes the pump-detection technology to realize the precise measurement of the ultrashort pulses in a time change process in different spatial positions in the whole airspace in a nonlinear transmission process, thereby simply, conveniently and quickly measuring the time change process of the ultrashort pulses in the differentspatial positions in the whole airspace in transmission, and having high measurement precision.

The invention discloses a novel method for realizing spectral combination amplification based on the frequency division multiplexing technology, which comprises the following steps of: (a), pre-amplifying and broadening laser pulse generated by an ultra-short pulse oscillator; (b), segmenting the frequency spectrum of a super-continuous broad-band spectrum into multiplex optical pulses with different central wavelengths; (c), amplifying each optical pulse, outputting a part of amplified seed light to a self-reference zero-frequency detection device by using a splitting slice, and taking a beat frequency signal output by the self-reference zero-frequency detection device as the driving frequency of an acousto-optic frequency shifter after filtering and amplifying; (d), coherently synthesizing amplification pulses output by various multi-stage optical fibre amplifiers through a wavelength division multiplexing beam combiner; and (e), carrying out dispersion compensation and pulse width compression of coherently synthesized pulses by using a compressor so as to obtain ultra-short pulse output with high peak power. According to the invention, the frequency division multiplexing technology and the coherent synthesizing technology are organically combined; therefore, the pulse synchronization problem and the spectrum coherent problem in the ultra-short pulse optical fibre laser coherent synthesizing process are solved.

The invention discloses a secondary chaotic encryption optical communication system based on phase transformation. The system comprises an optical signal transmitting device, a chaotic combined phase transformation encryption device, a transmission fiber, a chaotic combined phase transformation decryption device and a signal receiving device. The signal encryption part is a chaotic encryption module added with a phase transformation decryption device in a feedback loop, and the signal decryption device is an open-loop chaotic laser receiving module comprising a phase transformation decryption device. The system overcomes the defect that encryption variables of a chaotic encryption system are few; by combining phase transformation decryption with chaotic encryption, an eavesdropper is difficult in analyzing and attacking the energy; high-speed signals can be supported, and 10 Gb/s high-speed signals can be directly encrypted; a light emitting source of an existing WDM (Wavelength Division Multiplexing) system can be directly used for encrypting, and a special ultra-short pulse light source is not needed; and decryption can be implemented by using the same phase transformation modules at the receiving end as at the transmitting end, so that the adjusting difficulty is reduced without changing the confidentiality.

Solid-state laser(s) pumped by incoherent, monochromatic light from sources such as LED arrays and integrating technologies such as high power LED arrays and solid-state laser materials in conjunction with efficient and uniform absorption of pumping energies through a diffusing pump chamber. The resulting laser(s) are compact, robust, low-cost, and able to produce high power output for practical applications. It may efficiently operate over wide temperature and performance ranges, at CW or pulse modes, even with ultra short pulse width and/or extremely high repetition rates. Our inventive structure(s) is/are highly flexible and applicable to a large group of lasing media including those with very short upper state life times. Advantageously, they may be applied to a plethora of laser systems at wavelengths that have important applications and unavailable to other direct pumping technologies.

An ultra-short pulse laser beam output from a laser is diffracted into a plurality of laser beams, and a nozzle plate is scanned with the laser beams at a scanning speed of 40 mum/s to 300 mum/s. A placement position z of the nozzle plate with respect to a direction of an optical path of each laser beam is set to be -20 mum to +25 mum, where z is 0 at a reference position at which a hole diameter of the nozzle is minimum, and z increases as the placement position is moved closer to a source of the laser beam and decreases as the placement position is moved away from the source of the laser beam.

A small-sized, high-functionality optical pulse compressor capable of generating a low-power, high-repetition-frequency ultrashort pulse train used for ultralast optical communication and photometry, and a simple-structure optical function generator for realizing an arbitrary time waveform. The optical pulse compressor comprises and optical Fourier transform device (F) having an optical phase modulator (9) driven by the repetition-frequency of an input optical pulse train and a dispersive medium (8), for converting the shape of an input optical pulse frequency spectrum into its time waveform, and an optical filter (3) inserted ahead of the optical Fourier transform device (F), for reducing the spectrum width of an input optical pulse, wherein the optical Fourier transform device (F) converts a small-spectrum-width optical pulse output from the optical function generator generates an optical pulse. The optical function generator generates an optical pulse having an arbitrary time waveform by reproducing, as it is, a spectrum waveform-shaped arbitrarily by an optical filter on a time-axis by tch optical Fourier transform device (F).

A laser head generating ultrashort pulses is integrated with an active beam steering device in the head. Direct linkage with an application system by means of an adequate interface protocol enables the active device to be controlled directly by the application system.

The invention, which belongs to the field of laser processing, relates to a light beam-rotating galvanometer-scanning focused processing system. The system is mainly characterized in that: the system combines the light beam-rotating focused laser processing method and the galvanometer-scanning laser processing method into a novel processing method, which can form a wide cut, and thereby sprue can be conveniently spurted out; if the distribution of laser is Gaussian distribution, then laser processing has the laser processing effect of Gaussian intensity distribution, and has a laser processing effect capable of achieving flat-top laser; nanosecond laser is utilized to achieve the processing effect of ultrashort-pulse width laser, however, by comparison, the processing efficiency is greatly increased; the control is simple and flexible, the speed can be quickly increased and decreased, the size is small, and the cost is low.

A plastic object having a part whose structure has been modified by irradiation with a laser light having an ultrashort pulse duration of 10-12 second or shorter. The plastic object has a structurally modified part whose structure has been modified by irradiation with a laser light having a pulse duration of 10-12 second or shorter. The laser light having a pulse duration of 10-12 second or shorter may have an irradiation energy of 500 mW or lower. The plastic object may have the structurally modified part in an inner portion thereof. The structurally modified part preferably extends in a direction parallel or perpendicular to the direction of the laser light irradiation.

The invention discloses an ultra-short pulse dispersion reshaping and amplitude division technology-based ultrahigh-speed optical imaging system and an ultra-short pulse dispersion reshaping and amplitude division technology-based ultrahigh-speed optical imaging method. The optical imaging system comprises a femtosecond laser oscillator, an ultra-short sub pulse string generator, a femtosecond laser amplifier, an optical beam expanding system, an afocal optical system, a wavelength amplitude division optical system and a plurality of image recording systems. The optical imaging method comprises the following steps of: outputting a femtosecond laser pulse string; changing each pulse into a group of sub pulse string; amplifying each sub pulse; performing collimation and beam expansion on the amplified sub pulse; projecting the sub pulse subjected to the collimation and beam expansion to an object to be measured; propagating the sub pulse carrying object information of different moments along different directions; and receiving and recording the sub pulse of different directions. The system and the method can realize multi-image recording of dozens of picosecond to dozens of nano seconds process of picosecond time resolution.

In order to perform positional control of a condensing spot of pulsed laser beam highly accurately when performing optical modeling, optical recording or the like in optical machining technology, optical recording technology or the like which uses various kinds of pulsed laser, which are ultra-short pulsed lasers such as a femtosecond laser and short pulsed laser such as a picosecond laser and a sub-picosecond laser, as a light source, a pulsed laser system detects an output beam from a pulsed laser, controls laser oscillation of the pulsed laser based on the detection result such the output beam contains CW laser beam together with pulsed laser beam, and allows the pulsed laser to output the pulsed laser beam and the CW laser beam simultaneously as the output beam from the pulsed laser.

Systems, configurations and methods of using an ultrafast, self-starting, mode-locked laser are provided. The systems, devices and methods of using stable, self-starting mode-locked lasers, can be compact, use fewer optical elements and have energies sufficient for most micro-processing and micro-structuring applications. The large spectral bandwidth of ultra-short (femtosecond) laser pulses can be used in laser sensing applications, micro-machining, time-resolved experiments, where short-lived transient species can be observed in biological or chemical reactions. Terahertz radiation can be generated using ultrashort pulses and used for imaging applications.