Abstract: A multipulse-induced spectroscopy method based on a femtosecond plasma grating includes: pre-exciting a sample on a stage by providing a femtosecond pulse to form the femtosecond plasma grating; providing a post-pulse on the sample at an angle to excite the sample to generate a plasma, wherein the post-pulse comprises one or more femtosecond pulses, there is a time interval between the femtosecond pulse and the post-pulse, and the time interval is less than a lifetime of the femtosecond plasma grating; and receiving and analyzing a fluorescence emitted from the plasma to determine element information of the sample.

Abstract: A method for manufacturing a large-area volume grating includes: (1) splitting a laser beam into two or more laser beams, converging the two or more laser beams into a sample at an angle less than 60° to form a first plasma grating; (2) moving the sample in a longitudinal direction of a plane vertical to the first plasma grating to etch out a first prefabricated volume grating; (3) moving the sample laterally to form a second plasma grating, an effective cross section of the first prefabricated volume grating partially overlapping with that of the second plasma grating, then moving the sample in a longitudinal direction of a plane vertical to the second plasma grating to etch out a second prefabricated volume; and (4) repeating steps (2) and (3) n times to obtain a volume grating in any size.

Abstract: A method for film coating by pulsed laser deposition with a plasma grating includes: in step 1, providing a substrate and a target material; in step 2, generating a femtosecond pulsed laser beam which is split by a beam splitting module so as to form a plurality of femtosecond pulsed laser sub-beams; in step 3, performing a first excitation on the target material by one of the split femtosecond pulsed laser sub-beams as a pre-pulse after focus, to generate a first plasma; in step 4, synchronizing the rest of the split femtosecond pulsed laser sub-beams as post-pulses to form, after focus, filaments arriving at a surface of the target material simultaneously, to generate the plasma grating; and in step 5, performing a secondary excitation on the target material by the generated plasma grating to generate a second plasma depositing on the substrate to form the film.

Abstract: A method and a system for automatically controlling mode-locking of an optical frequency comb, where the stored control parameters of the working condition in the mode-locked state is combined with the collected working feedback parameters of the optical frequency comb system to dynamically adjust and control the working power of the pump source or/and the temperature of the working environment of the pump source, which not only greatly shortens the control time for stable mode-locking and realizes a fast mode-locking control, but also reduces unnecessary power consumption, thereby further guaranteeing the energy-saving effect of power adjustment control process. The present disclosure well maintains the stable working conditions of the optical comb system, and realizes the mode-locking optimization control of an update mode for the big data, thereby effectively improving the mode-locking control process of the optical frequency comb system, and providing higher operation stability and measurement accuracy.

Abstract: A detection method based on laser-induced breakdown spectroscopy enhanced by a two-dimensional plasma grating includes: generating a femtosecond laser pulse by a femtosecond laser, and splitting the femtosecond laser pulse into three sub-pulses by a beam splitting unit; focusing the three sub-pulses separately by a focusing unit to allow focused sub-pulses to be overlapped at an intersection in space, wherein before reaching the intersection, the three sub-pulses form two planes; synchronizing the three sub-pulses in a time domain by adjusting optical paths of the three sub-pulses in such a way that they have the same optical length and the three sub-pulses arrive at the intersection in space simultaneously and form the two-dimensional plasma grating; and exciting a sample on a stage based on the two-dimensional plasma grating to generate a plasma cluster, and acquiring a spectrum of the sample.

Abstract: A method for processing a micro-channel of a micro-fluidic chip using multi-focus ultrafast laser, in which an array-type multi-focus femtosecond laser is used to perform fractional ablation on the micro-fluidic chip, and then pulse laser is used to perform secondary ablation on the micro-fluidic chip. Ultrasonic-assisted hydrofluoric acid etching is performed on the micro-fluidic chip after ablation to obtain a true three-dimensional micro-channel on the micro-fluidic chip. A device for processing a micro-channel of a micro-fluidic chip using multi-focus ultrafast laser is also provided.

Abstract: A driving and stabilization system for a pump laser, and a pump laser system. The driving and stabilization system includes a constant current stabilization device, a constant temperature stabilization device, a power detection device, an environment detection device, and a control device. The constant current stabilization device includes a voltage comparison circuit, a constant current driving circuit, and a switch protection circuit. The constant temperature stabilization device includes an internal constant temperature stabilization circuit and an external constant temperature stabilization circuit.

Abstract: A divided-pulse laser regeneration amplification apparatus includes: a signal light coupling component including a first half-wave plate, a first polarization beam splitter, a first Faraday rotator and a second half-wave plate placed in sequence; and a divided-pulse laser regeneration amplification component including a second polarization beam splitter and a third reflector, the second polarization beam splitter is adjacent to the second half-wave plate and is in a same column as the third reflector and the second half-wave plate; a first quarter-wave plate, a Pockels cell and a first reflector are successively arranged on a first side of the second polarization beam splitter, and a third half-wave plate, a first pulse polarization separation component and a first non-linear pulse amplification component are successively arranged on a second side of the second polarization beam splitter.

Abstract: A device and a method for direct printing of a microfluidic chip based on a large-format array femtosecond laser. The large-format array femtosecond laser with multi-parameter adjustable laser beam state is used to achieve large-format laser interference. The interference state, interference combination and exposure mode of the large-format array femtosecond laser are regulated, and multiple exposures are superimposed to output the desired pattern for the microfluidic chip, enabling the direct printing processing of the microfluidic chip.

Abstract: The present disclosure provides a self-similar regenerative amplification method and an apparatus. The apparatus includes a broadband seed source, a spectrum shaping broader, a self-similar regenerative amplifier and a pulse compressor disposed in order of a light path. The spectrum shaping broader includes a time domain broader and a spectrum shaper. The time domain broader is configured to broaden the seed pulses, and fine-tune a width of the seed pulse. The spectrum shaper is configured to perform spectrum shaping on the broadened pulses to obtain saddle chirped pulses. The pulse regenerative amplification component includes a gain crystal and a nonlinear crystal. The self-similar regenerative amplifier receives the saddle chirped pulses, performs multiple stepwise amplifications and multiple nonlinear spectrum broadenings back and forth on the saddle chirped pulses, and output high-energy chirped pulses to the pulse compressor.

Abstract: The present disclosure provides a method of an ultrafast-pulsed laser deposition and a device thereof, wherein a single emitted femtosecond pulse is split, and the split pulses are synchronized in the time domain, and then coupled with each other to form a plasma grating or lattice to excite the target material once; then multiple pulsed lasers are sequentially coupled multiple times with the plasma gratings or lattices to excite the target material multiple times, and the excited target material is deposited and reacted on the substrate to form a thin film.

Abstract: A pulsed laser deposition method is provided. The method includes emitting a plurality of groups of femtosecond pulses, focusing the plurality of groups of femtosecond pulses into a plurality of groups of femtosecond filaments by lenses, and cross-coupling the plurality of groups of femtosecond filaments to form n beams of plasma gratings; exciting a target material by using a first plasma grating; and adjusting angles of the lenses and time delay between a plurality of beams of femtosecond pulses; coupling and splicing a second plasma grating with the first plasma grating along a grating pattern of the first plasma grating, until a nth plasma grating is coupled and spliced with a (n?1)th plasma grating along a grating pattern of the (n?1)th plasma grating to form a plasma grating channel; and exciting the target material by using the plasma grating channel to complete deposition on a substrate.

Abstract: A divided-pulse laser regeneration amplification apparatus includes: a signal light coupling component including a first half-wave plate, a first polarization beam splitter, a first Faraday rotator and a second half-wave plate placed in sequence; and a divided-pulse laser regeneration amplification component including a second polarization beam splitter and a third reflector, the second polarization beam splitter is adjacent to the second half-wave plate and is in a same column as the third reflector and the second half-wave plate; a first quarter-wave plate, a Pockels cell and a first reflector are successively arranged on a first side of the second polarization beam splitter, and a third half-wave plate, a first pulse polarization separation component and a first non-linear pulse amplification component are successively arranged on a second side of the second polarization beam splitter.

Abstract: A hyperspectral imaging method includes: providing time-domain synchronous mid-infrared ultrashort pulse and near-infrared ultrashort pulse as pump light and signal light, respectively; subjecting the signal light to optical time-stretching to broaden a pulse width of the signal light; directing the time-stretched signal light to a target sample to be detected; directing the pump light to a time delayer to adjust the time when the pump light reaches a silicon-based camera; spatially combining the time-stretched signal light from the target sample with the pump light from the time delayer; directing combined light to a silicon-based camera where the signal light is detected through non-degenerate two-photon absorption of the signal light under the action of the pump light to acquire hyperspectral imaging data; and obtaining an image of the target sample based on the hyperspectral imaging data.

Abstract: A device for fabricating a quartz microfluidic chip by a femtosecond pulse cluster. The device includes: a femtosecond pulse cluster laser source configured to output a femtosecond pulse cluster; a beam splitting and interference system, configured to split the femtosecond pulse cluster into a plurality of parts, and to converge split parts to form a femtosecond pulse cluster plasma or a femtosecond pulse cluster plasma grating; a sample system configured to move the electronic displacement platform where a quartz glass is placed to control a position where the parts of the femtosecond pulse cluster are converged on the quartz glass; and a hydrofluoric acid immersion system configured to immerse the quartz glass in a diluent hydrofluoric acid solution to remove an ablated part of the quartz glass to form the quartz microfluidic chip.

Abstract: A glass fiber filter element for visible light photocatalysis and air purification and a method for preparing the same. The glass fiber filter element includes 4 to 7 wt % of nanoparticles including at least one selected from zinc oxide, graphene oxide, titanium oxide, and reduced graphene oxide, 2 to 7 wt % of silver nanowires, 3 to 12 wt % of an adhesive system, and 78 to 91 wt % of a glass fiber mat, based on the total weight of the glass fiber filter element. The glass fiber mat is made of at least two glass fibers with different diameters, and the diameters are in a range of 0.15 to 3.5 ?m. The nanoparticles have a particle size from 1 to 200 nm, and the silver nanowires have a diameter of 15 to 50 nm.

Abstract: The present disclosure discloses a method and apparatus for preparing a femtosecond optical filament interference direct writing volume grating/chirped volume grating. The method is characterized in that optical filaments are formed in glass by using femtosecond pulse laser, and plasma is controlled to quickly scan in the glass and etch a volume grating or chirped volume grating structure by adjusting the focal length of convex lens, laser energy and movement of motor machine. The apparatus includes a femtosecond pulse laser module, a pulse chirp management module, a pulse time domain shaping module, a laser separation and interference module, a glass volume grating processing platform module and a camera online imaging module.

Abstract: A processing method and apparatus for ultrafast laser deposition of a multilayer film including a diamond-like carbon film, an anti-reflection film and an anti-fingerprint film includes: generating primary plasma by first excitement on a target material with a femtosecond or picosecond pulsed laser beam as a pre-pulse; and generating secondary plasma by second excitement on the target material under plasma grating, formed by allowing two femtosecond pulsed laser beams to intersect at a small include angle for interaction in the primary plasma, for deposition to coat a film.

Abstract: A method for film coating by pulsed laser deposition with a plasma grating includes: in step 1, providing a substrate and a target material; in step 2, generating a femtosecond pulsed laser beam which is split by a beam splitting module so as to form a plurality of femtosecond pulsed laser sub-beams; in step 3, performing a first excitation on the target material by one of the split femtosecond pulsed laser sub-beams as a pre-pulse after focus, to generate a first plasma; in step 4, synchronizing the rest of the split femtosecond pulsed laser sub-beams as post-pulses to form, after focus, filaments arriving at a surface of the target material simultaneously, to generate the plasma grating; and in step 5, performing a secondary excitation on the target material by the generated plasma grating to generate a second plasma depositing on the substrate to form the film.

Abstract: A method for preparing a graphene based composite wave-absorbing material includes: dissolving a water soluble barium salt and a water soluble iron salt into deionized water, respectively; mixing barium salt solution and iron salt solution according to a molar ratio of Ba:Fe of 1:12 to obtain a precursor solution; dispersing a graphene material in deionized water to form a graphene dispersion; adding citric acid, nitric acid and the graphene dispersion into the precursor solution in sequence to form a mixture solution; stirring the mixture solution at a temperature of 50 to 75° C. to obtain a sol; coating and drying aged sol on a substrate to obtain a coating layer; and sintering the coating layer by a laser irradiation.