15 results about "Laser pulse duration" patented technology

The invention discloses a low-repetition-frequency laser pointing stability improving device and method, and belongs to the field of lasers. According to the invention, the seed laser pulse of the MHz magnitude is used as the reference light to adjust the directivity of the light path, and compared with the main laser repetition frequency of the Hz magnitude, the sampling frequency of the subsequent directivity adjustment is greatly improved, so that the laser auto-collimation precision is improved. The use of the first shutter, the second shutter and the third shutter ensures the safety of the first detector and the second detector in the transmission process of the main laser when the energy difference between the main laser and the reference light is 9 orders of magnitude. The first detector images the first grating of the compressor to ensure that the positions of laser entering the compressor are the same, so that the consistency of laser pulse width and directivity can be ensured to a great extent, the second detector images the acting target to ensure that the acting positions are the same, and the stability of a subsequent radiation source is ensured. The laser directivity correction method is applied to laser directivity correction of hundred TW-level and PW-level lasers.

This invention relates to the field of laser ultrasonic nondestructive testing technology, specifically a method for optimizing laser source parameters during laser-induced ultrasound based on FEA (Feature-Enhanced Amplification). The invention obtains the geometric dimensions and material parameters of the insulator under test, constructs a geometric model, adds solid heat transfer and mechanical fields, and establishes a finite element model through thermal expansion coupling. Multiple laser pulse width and laser spot radius values ​​are determined and combined to obtain multiple parameter schemes. Each parameter scheme is applied to the finite element model as the time and spatial distribution parameters of the laser heat source, and transient calculations are performed. Displacement time-domain data of monitoring points are extracted and subjected to Fast Fourier Transform (FFT) to obtain frequency-domain data. The ultrasonic signal characteristics of each parameter scheme are compared and analyzed, and the parameter combination that meets the testing requirements is selected as the optimization result. This invention significantly reduces parameter optimization costs and improves testing efficiency through simulation-guided experiments.

A LIDAR system may include: a light generator configured to irradiate a laser to an object disposed in a blind section of the LIDAR system; a light receiver configured to sensing light reflected from the object; a receiver configured to receive a signal converted into an electric signal in the light receiver; a comparator configured to determine whether the signal is a voltage value which is equal to or greater than a predetermined reference; and a controller configured to control a pulse width of the laser irradiated to the object according to the determination.

The invention provides a laser control system and a laser control method. The laser control system comprises a laser output device, a temperature sensor and a controller, and the output end of the laser output device is configured to be implanted into a target intervertebral disc; the temperature sensor is configured to be integrated at the output end of the laser output device and used for acquiring the real-time temperature in the target intervertebral disc; the controller is used for determining at least one of laser output parameters of the next laser pulse on the basis of the real-time temperature and / or the real-time temperature rise rate until it is determined that the actual total heat of the laser output device reaches the target total heat; the laser output parameters comprise laser pulse width, laser pulse frequency, peak power and average power. A closed-loop feedback system is established, and the difference between the actual total heat and the target total heat can be calculated according to the real-time temperature and the real-time heating rate, so that the parameters of the next laser pulse combination are dynamically adjusted, and the target repairing effect is accurately achieved.

A method and device for determining distances to a scene determines a laser light pulse width PW that is smaller than a maximum time of flight TOFmax corresponding to a maximum distance Dmax by using a pulse width reduction factor N such that PW=(TOFmax−TDL) / N wherein TDL is a predefined delay window, determines a pulse frequency FP such that FP≤1 / ((N+1)×PW+TDL), illuminates the scene with an illuminating pattern comprising a plurality of spatially separated pulsed laser beams having the determined pulse width and frequency, performs the detection as function of time during a detection time period TD divided in M=α×(N+1) consecutive detection time windows, with α≥1, such that TD=M×(PW / α), identifies in what detection time windows reflected laser light is detected, and calculates a distance to the scene based on this identification.

The manufacturing method of a laser pulse width shortening film according to the present invention includes: a filling step in which a graphene oxide colloid is filled into a container having an open upper surface; a covering step in which a guide film having a predetermined outer pattern perforated therein covers an opening of the container; a bonding step in which the graphene oxide colloid is filled into the inside of the outer pattern by the capillary principle; an agglomeration step in which a solvent of the graphene oxide colloid evaporates in the inside of the outer pattern to form a graphene film by agglomerating graphene oxide molecules; and a separation step in which at least the graphene film is separated from the guide film.

The invention provides a processing method of a multi-stage blind hole printed circuit board and a circuit board, and belongs to the technical field of circuit board production, and the method comprises the steps: obtaining a printed circuit board; determining the parameter condition of the printed circuit board, and determining the diameter, depth and order of a to-be-processed blind hole in the printed circuit board; determining laser processing parameters according to the parameter condition of the printed circuit board and the diameter, depth and order of the to-be-processed blind hole; according to the determined laser processing parameters, multi-order blind holes are processed in the printed circuit board at a time without pretreatment through target laser; carrying out hole filling electroplating and subsequent process treatment on the processed blind hole; wherein the width of the target laser pulse is less than 10 picoseconds and belongs to an ultraviolet band. The method can effectively reduce the processing difficulty of the multi-stage blind hole of the circuit board, is beneficial to improving the production efficiency of the circuit board, and guarantees the production quality of the circuit board.

This invention provides a high-precision ultraviolet laser control system and method based on pulse width modulation, belonging to the field of laser control technology. It includes an ultraviolet laser generation module, a pulse width modulation module, a laser driving module, and a system control and monitoring module. The ultraviolet laser generation module generates ultraviolet laser light. The pulse width modulation module receives an external trigger signal and generates an electrical pulse signal based on a preset target pulse width value. The laser driving module converts the electrical pulse signal into a driving current to drive the ultraviolet laser generation module. The system control and monitoring module sets the target pulse width and target energy values, monitors the output characteristics of the ultraviolet laser in real time, and adjusts the peak value of the electrical pulse signal or driving current based on the output characteristics of the ultraviolet laser. This invention achieves high-precision and high-stability control of the ultraviolet laser pulse width and energy by combining electrical pulse width modulation with closed-loop feedback.

The invention provides a high-precision ultraviolet laser control system and method based on pulse width regulation and control, and relates to the technical field of laser control. Comprising an ultraviolet laser generation module, a pulse width regulation and control module, a laser driving module and a system control and monitoring module, the ultraviolet laser generation module is used for generating ultraviolet laser; the pulse width regulation and control module is used for receiving an external trigger signal and generating an electric pulse signal based on a preset target pulse width value; the laser driving module is used for converting the electric pulse signal into driving current and driving the ultraviolet laser generating module; the system control and monitoring module is used for setting a target pulse width value and a target energy value and monitoring the output characteristics of the ultraviolet laser in real time; and the peak value of the electric pulse signal or the driving current is adjusted based on the output characteristic of the ultraviolet laser. According to the invention, through combination of electrical pulse width regulation and closed loop feedback, high-precision and high-stability control of the pulse width and energy of the ultraviolet laser is realized.

Method for producing a micromechanical component (1) with a substrate (3) and with a cap (7) connected to the substrate (3) and enclosing a first cavern (5) with the substrate (3), wherein a first pressure prevails in the first cavern (5) and a first gas mixture with a first chemical composition is enclosed, wherein -- in a first process step (101) an access opening (11) connecting the first cavern (5) with a surrounding (9) of the micromechanical component (1) is formed in the substrate (3) or in the cap (7), wherein -- in a second process step (102) the first pressure and / or the first chemical composition is set in the first cavern (5), wherein -- in a third process step (103) the access opening (11) is closed by introducing energy or heat into an absorbing part of the substrate (3) or the cap (7) using a laser, characterized in that the introduction of the energy or heat is controlled by means of a time-shaped laser pulse (905) comprising a laser pulse duration (901) and a laser pulse intensity (903) in comparison to an unshaped laser pulse to reduce temperature gradients in the substrate (3) or in the cap (7), wherein the introduction of the energy or heat using the time-shaped laser pulse (905) is controlled such that the time-shaped laser pulse (905) includes a further laser pulse intensity (909) during a further laser pulse duration (907) preceding the laser pulse duration (901), wherein the further laser pulse intensity (909) is lower than the laser pulse intensity (903),wherein the introduction of energy or heat by means of the time-shaped laser pulse (905) is controlled in such a way that the further laser pulse duration (907) is at least partially temporally preceded by a first transition of the material region of the absorbing part from the solid to the liquid state of matter,

The invention belongs to the technical field of new energy lithium ion battery manufacturing, particularly relates to a surface pretreatment mode for battery welding, and aims to solve the problem that the existing current large cylindrical battery has many welding procedures including negative electrode collector plate welding, positive electrode collector plate welding, penetration welding, sealing nail welding and cover plate circumference welding. The number of welding procedures is large, the process yield is low, efficiency is low, and cost is high. Laser welding is high in base metal welding requirement and free of foreign matter and impurities. The method comprises the following steps that a welding system is composed of ultrafast pulse laser, a beam shaping device and a high-speed scanning galvanometer; the method comprises the steps that S1, a beam of ultrafast pulse laser is provided, the pulse width is smaller than 10 ns, and the repetition pulse frequency is larger than 200 KHZ; and S2, the ultrafast pulse laser is incident to a beam shaping device, a large number of organic foreign matter generated by electrolyte crystallization can be removed on the basis of high-intensity laser shock, and hole explosion, splashing and other defects occurring in the laser welding process are reduced.

The invention discloses a hybrid welding method and device integrating femtosecond copper etching and CFRTP red and blue laser, relates to the technical field of hybrid welding, and aims at conducting micro-nano structure pretreatment on the copper surface by introducing femtosecond laser before welding. Due to the fact that the duration time of femtosecond laser pulses is extremely short, energy is rapidly released on the surface layer of the material through the multi-photon absorption and transient ionization process, heat diffusion is hardly generated, and therefore a stable and controllable micro-nano-scale rough structure can be formed under the condition that copper surface melting or heat affected zone expansion is not caused. According to the micro-nano structure, on one hand, the original specular reflection characteristic of copper is destroyed, and the energy coupling efficiency of the micro-nano structure on follow-up welding laser is improved; and on the other hand, the actual contact area between copper and CFRTP molten resin is remarkably increased, an effective mechanical anchoring space is provided for resin permeation and curing, and the connection strength is improved from the interface structure level.

The invention relates to the technical field of laser ultrasonic nondestructive testing, in particular to an FEA-based laser light source parameter optimization method during laser excitation ultrasonic. The method comprises the following steps: acquiring geometric dimensions and material parameters of a post insulator to be detected, constructing a geometric model, adding a solid heat transfer physical field and a solid mechanical physical field, and establishing a finite element model through thermal expansion coupling; determining a plurality of laser pulse width values and laser spot radius values, combining the values to obtain a plurality of groups of parameter schemes, applying each parameter scheme as a time distribution parameter and a space distribution parameter of a laser heat source to the finite element model, and respectively performing transient calculation; extracting displacement time domain data of the monitoring points and performing fast Fourier transform to obtain frequency domain data; comparing and analyzing the ultrasonic signal characteristics of each group of parameter schemes, and selecting a parameter combination meeting the detection requirement as an optimization result. According to the method, through simulation guidance experiments, the parameter optimization cost is remarkably reduced, and the detection efficiency is improved.

The application discloses a kind of laser pulse width broadening device and system, its device includes pulse broadening structure, main control circuit structure and pulse polarization conversion structure, pulse broadening structure is used to be connected with seed oscillator, receives the laser pulse output by seed oscillator, and laser pulse is transmitted multiple annular, to make laser pulse broadening;Main control circuit is used for monitoring the transmission time of laser pulse in annular pulse broadening structure, when monitoring the transmission time of laser pulse reaches preset transmission time, polarization control instruction is sent;Pulse polarization conversion structure is connected with annular pulse broadening structure and main control circuit structure, for receiving polarization control instruction and laser pulse, the polarization state of laser pulse after broadening is adjusted, and from the port not connected with pulse broadening structure is output.The application can reuse the broadening characteristics of CFBG in annular structure pulse broadening structure, and laser pulse can be transmitted multiple annular, to make laser pulse broadening.

The invention belongs to the field of laser processing, and discloses a double-beam laser generating device, a laser processing system and application. The device sequentially comprises an optical fiber laser output interface, a laser collimation element, a Bragg acousto-optic modulator, a light beam included angle control element and a laser focusing element along a laser transmission path, wherein the input end of the radio frequency power source is connected with the signal generator, and the output end of the radio frequency power source is connected with the Bragg acousto-optic modulator. The device provided by the invention not only can meet the matching of laser pulse energy and pulse peak power density by independently regulating and controlling the width and power density of the laser pulse and realize high material removal rate of single laser pulse, but also can fully utilize the power of the laser beams through time modulation processing of double laser beams. Furthermore, the two laser beams are adopted in the system, a light beam regulation and control module and a platform control module are combined, and the machining quality and machining efficiency of application such as laser cleaning, laser engraving, laser texturing and laser welding can be improved.