12 results about "Nanosecond laser pulse" patented technology

The application discloses a disk medium high-energy ultra-short pulse laser regenerative amplifier based on CPA technology, comprising: a femtosecond laser seed light source for providing femtosecond seed light; a chirped Bragg fiber grating for expanding the femtosecond seed light into nanosecond laser pulses; an optical coupling input and output device for coupling input of the nanosecond laser pulses and coupling output of the nanosecond laser pulses after amplification processing; a regenerative amplification laser cavity for regenerative amplification processing of the coupled-in nanosecond laser pulses; the optical coupling input and output device comprises a fiber coupling collimation module, an optical isolator, a first 1 / 2 wave plate and a thin film polarizer; the regenerative amplification laser cavity comprises a Pockels cell, a second 1 / 2 wave plate, a first reflection module, a second reflection module, a first telescope module, a second telescope module, a first disk gain medium, a second disk gain medium and a third reflection module; the regenerative amplifier can realize high-repetition-frequency and high-pulse-energy laser pulse output.

The present application relates to a kind of electrode surface electrocatalysis process detection system based on transient raman spectrum, belong to raman spectrum technical field.It includes circuit part and transient raman spectrum test part, wherein circuit part includes signal generator, electrochemical workstation, computer, digital oscilloscope and resistance, transient raman spectrum test part includes pulse delay, in-situ raman cell, objective lens, double cemented lens, charge coupled device, silver mirror, narrow-band filter and raman filter.The present application has excellent adjustability and ease of use, using nanosecond laser pulse to detect the raman spectrum signal of reaction intermediate generated in electrochemical reaction process under the action of electric pulse, through the system, the dynamic process of electrocatalysis reaction can be accurately monitored and analyzed, which provides a powerful tool for studying electrochemical reaction mechanism.

The present invention relates to a device for generating sub-nanosecond laser pulses and pulse trains and a method for generating the same, comprising a semiconductor laser, a collimating and focusing system, a bonded or glued crystal, and a filter arranged in sequence along an optical path; the front and rear end face coatings of the bonded or glued crystals constitute a laser resonant cavity. The present invention achieves 1μm-band sub-nanosecond laser output by optimizing the length of the laser crystal, the small-signal transmittance T0 of the Cr:YAG crystal, and the pump light duty cycle; and then optimizes the pulse width and energy of the pump light to increase the pump intensity and achieve 1-20 pulse train modes of sub-nanosecond laser pulse output. The output sub-nanosecond laser pulses and pulse trains have high energy (>5mJ), high repetition rate (up to 1kHz), high efficiency, and high beam quality, meeting the requirements of high-efficiency and high-precision laser processing, greatly improving the efficiency and quality of laser processing.

The invention discloses a nanosecond-level high-voltage large-current narrow-pulse-width pulse power supply and an implementation method thereof, and belongs to the technical field of pulse power supplies. Comprising a power input module, a control and switch module, a transformer module, an inductance-capacitance filtering module and a reset and load module which are connected through standardized interfaces. Through operations of filtering, voltage transformation, pulse adjustment and the like on the input initial voltage, the effects of nanosecond laser pulse output, high voltage and large current output, small size, high stability, high reliability and good waveform consistency are achieved.

The invention belongs to the technical field of terahertz polarization devices, and particularly discloses a laser direct writing reconfigurable terahertz polarization device and a preparation method thereof. The preparation method comprises the following steps: sputtering a phase change material layer on one surface or two opposite surfaces of a substrate by adopting a magnetron sputtering process; and inducing a partial region of the phase-change material in the phase-change material layer to be converted from an amorphous state to a crystalline state by scanning nanosecond laser pulses at a high speed, and controlling a laser track through a galvanometer scanning system to print a grating structure so as to obtain the terahertz polarization device. The preparation method has the characteristics of no photoetching and high preparation efficiency, and the extinction ratio of the prepared terahertz polarization device is high.

The application provides a vacuum electroplating process and an electroplating device using nano silver ions to improve efficiency, which comprises the following steps: placing silver pieces into water, obtaining nano silver glue by irradiating with nanosecond laser pulses; adding a surfactant to the nano silver glue and obtaining highly dispersed nano silver particles by laser pulses; introducing argon gas with a certain pressure into a vacuum chamber, performing laser treatment on the surface of a substrate by pulse laser; adding the nano silver particles into the vacuum chamber, performing vacuum magnetron sputtering on the substrate, and projecting the focused laser pulses onto the surface of the required electroplating position of the substrate, so as to obtain an electroplated part; spraying a protective film on the electroplated surface of the electroplated part; performing laser treatment on the surface of the substrate by using pulse laser, then performing vacuum magnetron sputtering on the substrate, and projecting the focused laser pulses onto the surface of the required electroplating position of the substrate, so as to accurately lock the electroplating position and effectively improve the electroplating efficiency.

The invention discloses an optical pumping terahertz detection method and system, and relates to the technical field of optical pumping terahertz detection. The method comprises the following steps: constructing an optical pumping terahertz detection system; obtaining the terahertz time-domain spectrum of the sample: obtaining the amplitude of the terahertz time-domain spectrum, and changing the optical path difference between the detection light and the terahertz wave through an optical delay line and a reflection grating to realize time delay, thereby obtaining a complete terahertz time-domain spectrum; testing the photoconductivity dynamics of the sample: acquiring the terahertz signal amplitude change of the sample after optical excitation to obtain the photoconductivity change of the sample, and outputting subnanosecond laser pulses with different time delays by using a subnanosecond laser to realize time delay, and detecting the complete photoconductive dynamic change of the sample within the time scale from nanosecond to microsecond after optical excitation. According to the invention, the time delay of the pump light / probe light is realized by using the level signal, the terahertz dynamics from nanosecond to microsecond is detected, and the detection technology blank in the time scale in the field is filled.

This invention relates to a laser welding method based on variable pulse width dual pulses and a multi-scale observation system, belonging to the field of femtosecond laser welding application technology. The invention splits a femtosecond laser pulse into two femtosecond laser pulses. One of these pulses is spread into a picosecond-nanosecond pulse with adjustable pulse width using a pulse stretcher. The delay between the two pulses can be controlled using a delay translation stage. This allows the interface to be welded to first be irradiated by the picosecond-nanosecond laser pulse to generate a suitable thermal effect, followed by irradiation by the femtosecond laser pulse to form a "cold weld." By controlling the thermal phase transition process, welding efficiency and performance are improved. Combined with a multi-scale observation system, the welding process can be observed in real time from the femtosecond to the second scale. This invention has the advantages of high efficiency and simplicity, enabling high-quality, high-strength, and high-efficiency welding of difficult-to-machine dissimilar materials.

A laser device is disclosed that is configured to selectively operate in two different modes of operation: in a first mode of operation, the laser device is configured to output femtosecond laser pulses; and in a second mode of operation, the laser device is configured to output nanosecond laser pulses.

The invention relates to an electrode surface electro-catalysis process detection system based on transient Raman spectrum, and belongs to the technical field of Raman spectrum. Comprising a circuit part and a transient Raman spectrum testing part, the circuit part comprises a signal generator, an electrochemical workstation, a computer, a digital oscilloscope and a resistor, and the transient Raman spectrum testing part comprises a pulse delayer, an in-situ Raman cell, an objective lens, a doublet lens, a charge-coupled device, a silver mirror, a narrow-band optical filter and a Raman optical filter. The system has excellent adjustability and usability, Raman spectrum signals of reaction intermediates generated in the electrochemical reaction process under the action of electric pulses are detected through nanosecond laser pulses, the dynamic process of the electrocatalytic reaction can be accurately monitored and analyzed through the system, and a powerful tool is provided for studying the electrochemical reaction mechanism.

A laser device includes a laser module for generating a laser beam of sub-nanosecond laser pulses with a laser source, and arranged downstream of the laser module in a beam path of the laser beam, a deviating instrument for variable deviation of the laser beam in two spatial directions. The laser device further includes a focusing instrument for variable displacement of a focal point of the laser beam in a third spatial direction that corresponds to a propagation direction of the laser pulses.