Polyhedron rotating scanning mirror (PRM) has very important applications in the fields of ultra-high-speed cameras, ultrashort pulse micro/nano machining, laser scanning, and Q-switching. The natural frequency of PRM is crucial for PRM design. In this paper, the application of a topology-optimization technique to improve the fundamental natural frequency of PRM for ultra-high-speed cameras was proposed based on the solid isotropic material with the penalization method and the method of moving asymptotes to investigate the structural optimization design. Moreover, the internal structure of the PRM was optimized based on the pseudo-density distribution. In the optimized structure, the three sharp corners with smaller pseudo-density material were removed and replaced by three irregular holes and three circular apertures with the same radius. Under identical conditions, the first natural frequency of the optimization structure was promoted from 4, 746.3 Hz to 5, 366.1 Hz, increased by 13.1%, which represents an obvious improvement in the image quality obtained by using ultra-high-speed cameras. The topology-optimization model and corresponding methodology reported herein provide a perspective and application area to effectively improve the fundamental frequency of a PRM without changing the external structure of this component

With the continuous increase of urban electricity consumption in China, power transformers’ vibration and noise pollution problems have gradually aroused extensive attention. The vibration and noise were mainly sourced from magnetostriction under sinusoidal current excitation for a transformer. The vibration can be transferred to the oil tank via the supporting feet on the bottom, transferring both vibration and noise in the transformer toward the transformer surface and the external environment. To effectively control the vibration transmission, this study first conducted optimization analysis and simulation on the vibration of the transformer body with particle swarm optimization (PSO) algorithm. It determined the optimal dynamic parameters of the transformer. Next, the porous rubber damper was designed and installed in an actual transformer to reduce vibration transmission from the main body to the oil tanker. Finally, vibration isolation and noise reduction experiments were also carried out. It was found that the developed porous rubber damper showed obvious vibration inhibit performance, with an overall noise reduction of up to 6.4 dB(A). The present study can provide an effective solution for transformers’ vibration and noise control.

Based on the counting method for clock pulse subdivision which measures the gear transmission error, the torsional vibration model of the gear transmission error test platform has been established to solve the problem that the measurement accuracy is susceptible to resonance when the natural frequency of the measurement system of gear transmission error is identical to that of the excitation frequency. In this study, the natural frequency of the transmission system was calculated and verified by the sweep frequency test. By analyzing the sweep frequency response curve of the direct connecting shaft and gear pair, the transmission components were weakened so that the test speed of transmission error could fall into the non-resonant flat interval between the first-order and second-order natural frequency. The optimal speed range of the tested gear pair was tested by scanning frequency. The measurement results not only avoid interference frequency but also possess good repeatability, providing a reliable and accurate measurement technology for vibration and noise reduction of gear minor modification.

A CMOS (Complementary Metal Oxide Semiconductor) industrial camera based on EFINIX FPGA (field programmable gate array) was designed to solve the shortage of chips for high-performance industrial cameras in China. GLUX9701BSI (Gpixel), SCB13H4G160AF-11MI (UnilC), and CH569 (WCH) are applied as an image sensor, a memory module, and a data output module respectively. The overall structure of the camera is illustrated systematically and specifically as well as the design of the hardware circuit. The experimental results show that images can be uploaded to the host computer via USB 3.0 interface stably at high speed. It is a monochrome camera in visible light equipped with an all-pass filter, while it is an ultraviolet (UV) camera in UV light equipped with a low-pass filter. The camera supports a high dynamic range of 79.9 dB and an ultra-wide spectral response of 200-1100 nm. But the power consumption of the camera is only 1.3 W. The key technical specifications have reached or exceeded the overseas products of the same kind, but the price is only 40% of similar products abroad. The design realizes the comprehensive China core of high-speed industrial cameras, breaks the bottleneck of a long-term dependence on imports for industrial cameras, and relieves the shortage of chips for industrial cameras in the domestic market.

Ultraviolet rays are constantly affecting human health, especially causing harm to the eyes. Therefore, anti ultraviolet glasses and lenses are of great significance for human health and safety. At present, there are simple and qualitative testing equipment for the UV protection performance of lenses, but their measurement accuracy and traceability have not been verified. Accurate and quantitative UV protection testing requires the use of high-precision grating spectrometers, making it impossible to conduct on-site testing. Therefore, this article presents a portable anti-UV detection system for eyeglass lens, integrating electronic components such as UV light sources, UV sensors, micro-controllers, and display screen. Experimental verification has shown that the system can meet the testing requirements of various lenses in the market.

Phase laser ranging technology is a significant approach for large-scale and high-precision measurement. Improving the precision of phase ranging by increasing the modulation frequency is considered as one of the most effective methods. However, the maximum sampling frequency of A/D devices limits the sampling rate of high-frequency modulated signals, which means that the modulation frequency cannot be increased infinitely. So, the using of under-sampling for high-speed and highfrequency modulation signals is proposed in this paper. The feasibility of this method is analyzed and verified. For further improvement in ranging precision, the advantage of all phase fast Fourier transform (apFFT) is analyzed by simulation. In addition, Kalman filtering technology is adopted in this paper to suppress noise in the system to improve the precision of phase discrimination. Based on the simulation results, a high-precision phase discrimination system using FPGA is designed in this paper. According to experimental results, when the modulation frequency is 1.616GHz and the sampling frequency is 1.6GHz, the ranging stability of the system can reach ±10.8ߤ݉ and the speed of phase discrimination can reach 2712 times per second.

To overcome the defects of the poor measurement precision, the low efficiency and the fussy manual work existing in the current methods for measuring the inner diameter of small-caliber tube, based the high precision inductive displacement transducer and the principle about radial and axial conversion, a new electromechanical measuring system is designed. Moreover, this paper expounds the form and the measuring principle, and analyzes the measuring precision in detail. The metering results show the measurement accuracy of the system is superior to 0.01mm, and can suffice the test requirement at the testing ground.

In order to optimize the specrum of Fano resonance at multiple positions at the same time and maximize the value of multiple Fano resonances, this paper proposes a new asymmetric dual microring coupled device structure. In this structure, two air holes are embedded in the bus waveguide as reflection units to form a Fabry-Perot (FP) cavity, and two microrings with different radii are coupled on the upper and lower sides of the bus waveguide to achieve double Fano resonance. The transmission spectrum of the proposed device structure and the electric field distribution of the resonant cavity are simulated by using the finite difference time domain (FDTD) method. The frequency and line shape of the Fano resonance are changed by dynamically changing the refractive index of the upper and lower microring resonator parts, thereby realizing independent tunability of the dual Fano. The proposed asymmetric double microring coupled resonator has a single resonant peak extinction ratio of up to 35.95 dB and a slope of 189.2 dB/nm. The device proposed in this paper has good independent tunability, simple structure and sufficient flexibility, which can be used in multi-wavelength optical switches, dual-function sensors and other occasions.

In this paper, we have reported a method for Raman spectroscopy enhancement based on microsphere array chips. As an ideal and easily integrated optical microlens, dielectric microspheres have the advantages of small size and easy integration. In addition, the array of dielectric microspheres can accomplish high-density, high-throughput multi-detection mode, and its unique PNJ (photogenic nano-jet) effect can make the focusing intensity greatly improved, which can enhance the intensity of Raman spectrum in a limited way. The experimental results have shown that the microsphere array chip has significantly enhanced the detection sensitivity of liquid samples, with an enhancement factor of nearly 3.5 times and a relative standard deviation of only 7.760%. It can be seen that this method has the advantages of simple structure, wide application range and non-contact, which can effectively improve the detection sensitivity of liquid Raman spectroscopy.

In this paper, we have proposed and fabricated a novel Raman sensor with an internal metal-plated hollow-core fiber, and the core device of this sensor is a hollow-core fiber with an internal silver coating. The large aperture diameter of the hollow core fiber with internal metal plating enables fast sample switching, and also allows simultaneous transmission of excitation light and sample, increasing the volume of light-sample interaction to be measured and improving the collection efficiency of Raman signals. The experimental results have shown that the Raman signal is enhanced by a factor of 4.24 using the hollow core fiber with internal metal plating compared with that using the hollow core fiber without internal metal plating, which has the potential of high sensitivity, high stability and on-line detection.

The oblique incidence measurement system that can eliminate multiple interference background interference in the measurement of the hypotenuse-face of rectangular-prism is studied, and an upright oblique incidence measurement device that can directly measure the hypotenuse-face of rectangular-prism is designed. The device includes a phase-shift interferometer host, integrated loading table and a pair of reference flats. The multiple interference background errors caused by the ray cluster caused by the reflection of the rectangular surface are discussed. The method of 3D deflection is used to avoid the interference of the total internal reflection ray to the measurement of the hypotenuse-face of the rectangular-prism. An upright phase-shift interferometer based on oblique incidence was assembled, and the optical path adjustment and parameter calibration were completed. The measurement of the hypotenuse-face of the rectangular-prism was realized. The white light profiler was used to measure the hypotenuse-face of the measured prism, and the results were consistent. It solves the measurement problem of the rectangular-prism strips, realizes the industrialized online measurement of microprisms, and has important applications in the processing of rectangular-prisms

Spatially controllable focal fields play a pivotal role in modern optical engineering, offering opportunities for precise manipulation of light-matter interactions in various applications. Double-helix focal fields, in particular, have gained attention due to their unique helix structure that exhibit distinct optical properties. In this paper, we propose a method for generating a controllable spatial double-helix focal field without optimization. This is accomplished by utilizing the radiation pattern of a virtual helix antenna consisting of magnetic units, which is reverse-focused in a 4π-system. Numerical results indicate that the double-helix focal field can be flexibly customized by selecting the shape and parameters of the helix antenna. The novel and customizable double-helix focal field expands the applications of optical engineering in complex opto-fluidics and optical lithography.

In order to improve the convenience and the efficiency of the asphalt pavement surface wear test, we provided a intelligent detection method based on 3D and 2D pavement surface texture information. We collected the actual pavement surface texture data by a handheld laser 3D scanner and a smartphone. With the 3D points data cloud, we calculated the pavement wear index (PWI) to grade the road surface wear status and extracted of several interested parameters. According to the grading of road surface wear status from the 3D data cloud, the corresponding 2D mobile images were labeled and the training set and test set for neural network training were established. Finally we used a improved ResNet50 network to build a classifier, and tested the classifier performance. The result showed that this method could quickly and effectively predict and classify the road wear state with an accuracy of 94.17% which was adequate for road wear detection.

With the increasing requirement of strength test technology, machine vision non-contact measurement system is more and more used in aircraft strength test. In this paper, the typical machine vision non-contact measurement model as the research object, through its principle and measurement characteristics are described and analyzed, an innovative calibration method of machine vision non-contact measurement system is proposed, and how to process the calibration data is analyzed, the source of uncertainty in the calibration process is determined, and the calibration results are evaluated for uncertainty.

In order to address the lightweight problem of certain structures in the support components of space cameras, a topology optimization method is proposed for design of the support structures. A mathematical model based on the topology optimization theory of continuum structure is established. The NX topology optimization module is used to optimize the bottom support structure of a space camera. Moreover, the basic principle of random vibration analysis is expounded, and the mathematical model based on random vibration response analysis is established. Subsequently, the random vibration response analysis is conducted on the entire instrument, obtaining the root mean square response values of the acceleration of the weak part diaphragm. The results of design and analysis indicate that using topology optimization design methods can effectively reduce the weight of the bottom support structure and improve the performance of the support structure. Additionally, the finite element analysis method based on the basic principle of random vibration can calculate the root mean square response value of acceleration at weak parts, thereby validating compliance with requirements.

Welding defect detection is an important means to ensure the quality of welding, and also an essential part of manufacturing quality inspection. In order to improve the flexibility of weld quality inspection, this study adopts two different object detection algorithms, YOLOv5 and YOLOv7, to detect cracks in the collected datasets of spot welding crack using Eddy Current Infrared Thermography. The performance metrics are used to evaluate the model's effectiveness and determine the most suitable detection model for weld crack detection. The experiments show that YOLOv7 is more suitable as the detection model for spot welding crack detection, which can achieve better results in terms of detection accuracy and detection speed, and meets the requirements of high detection accuracy and fast detection speed in practical industrial applications.

Laser scribing graphene (LSG) has provided a facile and effective strategy for graphene formation via direct laser scribing on polymer substrates. The outstanding properties make it highly impending to be a key building block for highperformance composites to realize multifunctional applications. Aiming to facilitate the integration of LSG with composites, here we report a novel process for LSG production by using cyanate ester-based composites (CEC) as the precursor. Systematic characterization, test and evaluation were performed to explore the processing-structure-property relationship of CEC-based LSG. It was found that CEC-based LSG possessed a better conductivity (785Ω/sq), which is attributed to the high degree of laser graphitization. The resulting LSG promises CEC broader capabilities. We demonstrated the LSG-based composites did well in in-situ curing process monitoring and liquid sensing applications. With straightforward manufacturing process and excellent working performance, the expanding applications of LSG composites are foreseen.

In this paper, the structure of the existing cell factory microscopic observation system is improved and perfected. Through reasonable structural design and space utilization, the volume of the instrument is reduced as far as possible under the premise of realizing the function of the motion system. In the microscopic observation system of cell factory, the main bearing plate is bent by the loading of the medium, and the deformation will affect the observation effect of the bottom lens camera on the bottom. The shape variables of the bearing parts of the side lens will directly affect the observation of cell growth in each layer of the cell factory by the side lens. The mechanical properties are analyzed in this paper. Firstly, the three-dimensional models of the main bearing plate and the bearing parts of the side lens are established. Then, the model is imported into the finite element analysis module, the relevant material properties are defined, the cell grid is divided, the load type is set and solved. The results showed that the payload of the 10-layer cell factory was 39.2N, the maximum stress of the main bearing plate was 4.5MPa, and the maximum variable was 0.0026mm. The bearing part of the side lens is subjected to the maximum stress of 11.832MP, the maximum deformation of 0.135mm, and the yield strength of the material is 55MP.From the above analysis results, it can be seen that the mechanical properties of the main bearing plate and the bearing parts of the side lens of the cell factory reactor meet the requirements of use under the action of load. Real-time monitoring of 1-10 layer cell factories is realized.

Hyperspectral imaging technology has undergone rapid development in recent years. However, with the exponential growth of data volume, the difficulty of data processing is also increasing rapidly. In such an environment, various target detection algorithms are constantly emerging according to different application environments. In view of this, this paper constructs a Knowledge graph based on hyperspectral anomaly detection algorithm on the neo4j platform, and simply summarizes and sorts out the scattered algorithms. Based on the construction method, we believe that the graph we have constructed has great development prospects in recommending hyperspectral target detection algorithms.

Event cameras, offering extremely high temporal resolution and high dynamic range, have provided a new solution to the challenges of space object detection, such as high light, low light and motion blur. However, the asynchronous output characteristics of event cameras make it incompatible with traditional object detection algorithms designed for frame images. Therefore, a new deep network architecture is proposed. First, the asynchronous event streams are characterized by event spike tensor (EST), then extract spatial features using a feed-forward feature extraction network, and finally the end-to-end object detection using continuous event streams is realized. The proposed method is compared with the classical object detection algorithms on the synthetic event stream dataset. The results show that in scenes (high light and low light) where traditional optical cameras fail, event cameras still perform well, and the mAP is improved by 4.2%. This study offers new possibilities for using event cameras for object detection under complex lighting environments and motion conditions, and highlights the advantages of event cameras in space object detection.

To address the issue of noise interference in weak light signal detection, this paper presents a fully symmetric differential amplification circuit structure. An equivalent circuit model is constructed to analyze the noise factors affecting circuit performance. The TINA simulation software is employed to simulate the total noise voltage of the system. Subsequently, a weak optical signal detection system is designed using a transimpedance amplifier and an InGaAs-PIN. The system's detection error is compared with that of the foreign variable gain low noise current amplifier (DLPCA-200). Experimental results demonstrate that the proposed circuit structure effectively reduces system noise, enabling accurate detection of weak light signals.

According to the Newtonian ring in different thicknesses of air film will show light and dark fringes, using convex lens and flat glass to improve the Young's modulus measuring device of metal wire, through Newton ring light and dark fringes change times to calculate the change of metal wire elongation. The experimental results show that the surface measurement error is small, which can effectively improve the measurement precision. The device can calculate the Young's modulus of the material by observing the corresponding distance change of the Newton ring, so as to infer the degree of flexibility of the material, and accurately measure the Young's modulus of the material, so it can be applied in the field of materials research.

With the development of the times, due to the pursuit of healthy diet, people are paying more and more attention to the safety of vegetables and fruits. In recent years, there have been frequent safety issues in fruits and vegetables in China. The abuse of pesticides has made it difficult to clean residual pesticides on fruits and vegetables, and residual pesticides have a significant impact on physical health. In the past, relying on the experience of fruit farmers to judge has become outdated, and the cost of chemical colorimetric detection technology and other technologies is high and complex. Therefore, the use of hyperspectral technology for vegetable and fruit detection has become the mainstream detection method in recent years. This technology can analyze crops through spectroscopy, and use machine learning algorithms to process the data. This article will introduce the progress and methods achieved in the application of hyperspectral technology in fruit and vegetable detection in the past six years, for the convenience of scientific researchers for reference.

An automatic processing device of strain gauge in the force sensor was designed to solve the low machining efficiency, poor accuracy, uniformity and consistency. Based on the principle of electropolishing, the corrosion process of strain gauge and the resistance measurement process were integrated to realize accurate and efficient machining of the strain gauge in the force sensor. Results show that the processing accuracy, consistency and efficiency of strain gauge in force sensor could be significantly improved by using this device. The dispersion degree of the processed strain gauge parameters of the force sensor had been reduced by about 40%, the consistency of the thickness distribution was significantly improved, and the average processing time was shortened by more than 60%, which effectively improved the quality of the strain gauge of the force sensor and the long-term stability.

The detection of the spindle attitude for the mine hoist stands as a critical component within the scope of deformation monitoring in the coal mine industrial square. To tackle the challenges arising from considerable measurement space, stringent accuracy requirements, and insignificant feature elements, a combined measurement method is introduced, with the laser tracker as its nucleus. This method enables the dynamic tracking measurement of the circular running trajectory of the hoist's double-side profiles with the help of a laser tracker. Subsequently, through fitting procedures, the three-dimensional coordinates of the hoist spindle are calculated. In the aftermath, it facilitates the resolution of attitude parameters such as the inclination angle and the deflection angle of the hoist. Empirical observations demonstrate that the measurement error of the laser tracker's running trajectory is superior to ± 0.1 mm. Additionally, the residual of coordinate transformation between the winch room and the industrial square remains within ± 0.8 mm. In comparison with the conventional combined measurement method utilizing theodolite intersection, this approach enhances working efficiency by over twice the previous rate.

A method of extracting the contour of moving images based on three-dimensional lidar is studied. The attitude point cloud information in the original moving image was discretized, the maximum threshold was set to remove the noise and occlusion point information, and the attitude rotation characteristics were defined according to the curvature of the moving image.

Laser lighting is the future development trend, but it is still not popularized in China. In this paper, we use the LucidShape software to simulate the far-light reflective cup of an automobile and design the middle and high-end models of the universal laser bulb. By using the ray tracing software (TracePro) simulation, it can illuminate about 100 meters. The illumination of a 10.5-watt blue laser is more than 4 times that of a 60-watt halogen bulb. The quantum efficiency of the phosphor, molar extinction coefficient, and molarity are calculated and matched. Blue light is shined on the phosphor to obtain white light. The beam emitted by three 3.5-watt blue lasers is combined, and the beam after the combination will converge and then collimate to irradiate the phosphor to excite yellow light. According to the principle of the additive color method, yellow light and the remaining blue light are mixed to obtain white light. For the high-beam headlights, the fog lamp function is taken into account. The special structure of the phosphor shape can make the middle of the road spot produce white light and yellow light on both sides. The distant target can be found in time on foggy days. If a new type of high beam assembly is developed, it is possible to set up a reflective cup, 10.5 watts of light power irradiation distance of more than 200 meters and put forward the LD/LED program and LED high beam two in one.

As an important component of intelligent connected vehicles, intelligent rearview mirrors can provide visual assistance to drivers and improve their operability of the vehicle. As a Class A electrical component that affects the driver's driving safety, its electromagnetic anti-interference performance will affect the reliability and safety of the entire vehicle. By arranging the tested vehicle equipped with intelligent rearview mirrors in a 10 meter semi anechoic chamber according to standard requirements, the electromagnetic anti-interference performance of the intelligent rearview mirror is evaluated using a light intensity monitoring system. The light intensity monitoring system can solve the error problems caused by testing equipment, human factors, and other factors in the existing experimental process. By storing the test data on the light intensity monitoring system in real-time, it achieves the standard requirements of quantifiable, evaluable, and traceable test results.

The dielectric composite nanostructures (DCN) composed of non-closely hexagonal packed SiN_x nanodomes and their underlying SiN_x single film were demonstrated, which aims for decorating single-junction GaAs solar cells to reduce their surface reflection. The broadband antireflection performance for this DCN was experimentally measured, with the average reflectivity of 3.11% in the spectrum range from 300 nm to 920 nm, which is attributed to the combination of multiple modes including Mie resonance scattering, guided-mode resonance, etc., and that was verified by the theoretically modelling using finite difference time domain (FDTD) method. The simulation results indicate that this DCN is capable of improving the performance of the GaAs solar cells in terms of broadband antireflection and highly efficient light trapping properties.

This paper reports our studies of a novel erbium-doped (ED) fiber inter-coupling three-ring laser (TR-L) system, where three ED fiber single-ring lasers are inter-coupled by three couplers to form this kind of laser. Thereout, our work establishes the laser physical theory of the TR-L system, and studies its bifurcation behavior in detail. The dynamical behavior evolving from a steady behavior through a double-period to a chaotic behavior is introduced via phase parametrization to reveal a path to some chaotic behaviors from double-period to pass through some quasi-periodic bifurcations by shifting one parameter of the laser. Numerical phase-parametric diagrams exhibit quasi-period bifurcation via adjusting the pump strength or the ring coupling levels. The chaotic region and quasi-period bifurcation region are found. Period-one, quasi-period, and chaos are numerically presented to show rich nonlinear dynamic phenomena. The fiber laser gives an important value to study laser systems, chaotic optics emitters, random optics signal generators, measuring devices, and encoding communications.

In this paper, from the SIMULINK visual modeling requirements, the rate equations of the master-slave semiconductor lasers are derived and improved, the corresponding models are constructed, and the rate equations are calculated using the fourth-order Runge-Kutta algorithm. Finally, this visualization model is used to study the effects of delay parameter and injection intensity on the chaotic synchronous communication performance of the optical injection feedback semiconductor laser. The results show that the increasing injection intensity leads to an increasing number of master-slave semiconductor laser interrelationships, while the magnitude of the delay parameter has little effect on the degree of interrelationship of the chaotic synchronous system.

In response to the urgent application demand for wide-field of view optical observation systems in the detector field photometry field, there are currently several implementations of wide-field of view detector field photometry systems. These include the use of multiple optical system field of view stitching, increasing the detector CCD target surface, focal plane stitching combined with post-image processing, etc., all of which have relatively high costs. This paper proposes to achieve a wide-field of view effect using the detector stitching method of a coaxial optical system. The research object is a wide-field of view optical system with a relative aperture of 1/4, a focal length of 60mm-180mm, and a dual detector stitching of 1920×1080. Based on the optomechanical coupling design method, the optical mechanism type and material were determined. With the support of finite element simulation technology, the optical system's self-weight deformation analysis was conducted. A dual-detector stitching assembly scheme was proposed, and the development of a wide-field of view optical system with internal stitching of dual detectors was achieved. The feasibility of this approach was preliminarily validated. This method only requires a single optical system, compared to the approach of using multiple optical systems. It also does not require a larger CCD target surface, compared to the approach of increasing the CCD target surface. This paper provides a reference route for the development of wide-field of view optical systems.

In recent years, under the promotion of the rapid development of science and technology and information technology, the technology of obtaining low altitude and high resolution has also become increasingly mature. The development of GPS technology and IMU devices and the increasing miniaturization of aircraft design make the design of aerial camera optical systems increasingly diversified. This paper mainly designs an inverse remote optical system about aspherical surface, and initially selects the parameters of its optical performance. At the same time, the structure of the optical system is analyzed, including the global plane structure and the optical path structure of the aspherical structure, and the imaging quality is designed, including MTF curve, point diagram, and map. The data of system aberration curve and relative illuminance are analyzed and studied. It is found that the use of aspherical lens makes the design of optical system more complicated and diversified, and the high resolution of aspherical lens is proved.

In this paper, a small air-cooled, heat-dissipating VCSEL end-face pumped disc laser is designed, which is end-face pumped with Nd: YVO₄ crystal in VCSEL arrays. The pump source and gain medium are mounted on the same heat sink, and the water-cooled and air-cooled heat dissipation systems are compared and simulated by ANSYS and Flow Simulation software, respectively, which verifies the feasibility of the air-cooled heat dissipation model; an aspherical lens is designed to complete the collimation of the VCSEL array by ZEMAX, and the dispersion angle of the X and Y directions after the collimation is 0.47°; A parabolic reflecting focusing mirror is designed to collect the collimated beams, and the size of the focused spot is 1.52mm×1.52mm. The heat sink is optimised by flow simulation, and the best heat dissipation effect is obtained with the parameters of fin thickness of 2mm, fin height of 37mm and fin spacing of 3mm. The overall design of the air-cooled, heat-sink VCSEL-pumped disc laser is carried out by Soilworks, and the overall dimensions of the laser are 120mm×90mm×90mm (length×width×height) (of which the length of the heat-sink system is 40mm).

Electron multiplier tube can be used in the field of electron beam measurement, which can be used to measure the small current electron beam after amplification. In the measurement, in addition to the internal error of the multiplier tube, different incident electron beams will also affect the magnification of the multiplier tube. In order to analyze the error of different incident electron beam parameters on the electron multiplier tube, this paper uses CST to establish the electron multiplier tube model. After verifying the correctness of the simulation model, the energy, incident angle and radius of the incident electron beam are simulated and analyzed. The simulation results show that The parameters of the incident electron beam mainly affect the first multiplication electrode, including its collection efficiency and the number of secondary electrons generated, and ultimately affect the magnification of the electron multiplier tube.

This reports out studies of dynamics and bifurcation in a NH3 laser using Zeghlach-Mandel model. We analyse theoretically dynamics stability of the laser in the three stable state using the eigenvalue equation, and give numerical discussions of dynamics stability of the laser in the three stable state using the eigenvalue. We find that there is the exponential contraction of the phase space volume element of the laser. The dynamical evolvement starting at a stable state through a periodic bifurcation to chaos is analyzed via the bifurcation diagram to give a path to chaos through quasi-periodic bifurcation scenario with different starting values. Numerical bifurcation diagram exhibits quasi-periodic bifurcation from a stable state by adjusting the pump rates. It can be clearly found that the laser moves around its unmovement points and is eventually attracted to one of the points, and it is sensitive to the initial value. The chaotic region and quasi-periodic bifurcation region are found. The movement orbits of a stationary state, quasi-period, and chaos are numerically exhibited to show rich nonlinear dynamic behaviors. The laser gives an important value to study laser systems, chaotic optics emitters, random optics signal generators, precision optics measuring devices, and optic encoding communications.

In order to reasonably select the structural dimensions of key components of the photoelectric turntable, size optimization research was conducted on the main load-bearing parts of the photoelectric turntable, such as the reducer bracket, pitch frame, and transmission shaft, using ISIGHT software. Firstly, the main structural dimensions of the key components of the turntable are used as optimization variables, and the maximum stress, maximum strain, and first-order natural frequency of the turntable model in finite element simulation are used as constraints. The mass is taken as the optimization objective, and sample points are selected using the Latin hypercube sampling; Then, based on the set of sample points, the approximate model is trained using the RBF algorithm; Finally, a set of optimal size parameters were obtained by optimizing the approximate model size using a multi-island genetic algorithm. The results show that compared to before optimization, the total mass of key components of the optimized turntable has decreased by 28.8%, and the optimization effect is good.

Thanks to their striking visual appeal, grayscale moiré pattern have a high potential for document, security, art, and decoration. In recent years, researchers have paid extensive attention to using microlens arrays instead of micrographic arrays as the base layer to achieve novel moiré effects in moiré magnifiers. In order to reduce the thickness of the grayscale imaging device and increase the dots per inch (DPI) of the grayscale image, we proposed a reflective grayscale moiré imaging device. By using a curved microcylindrical lens array (CMCLA) with a metal reflector layer deposited on the surface as the base layer, the reflective device achieves a similar grayscale effect as the transmissive device with a smaller offset in the base layer, thereby increasing the fill factor of CMCLA. Applications of such devices can be found in the protection of valuable items against forgery.

Due to its thinness and large focal depth range, micro lens array (MLA) based projectors possess high potential in automotive lighting, traffic signs, and short-distance projection. Recently, researchers have paid extensive attention to projectors that employ micro lens arrays as projection lenses and transmissive chromium layers as masks. In order to expand the application scope of such projectors, we have developed a projection device capable of projecting grayscale images. By specially designing the mask pattern for each micro lens, the projected image from each sub-aperture is different, resulting in varying illuminance levels in different parts of the overlaid image on the image plane. This design method enables the projector to project fine grayscale images without requiring high-precision lithography equipment.

To enhance the efficiency of infrared missile development and testing, cryogenic chamber semi-physical simulation was employed for the low-temperature infrared radiation calibration of a seeker. The collimation system, a pivotal subsystem of the cryogenic chamber, is primarily responsible for generating far-field radiation during testing. An off-axis three-mirror collimation system tailored for low-temperature applications is proposed. The entire collimation system employs a SiC athermal structure to enhance its adaptability to low temperatures. The primary mirror of the collimation system undergoes thermal-structural-optical integrated simulation analysis, addressing four key factors: gasket diameter, temperature difference between the mirror and its support, unloading groove, and flexible element. At low temperatures, the surface error of the primary, secondary, and tertiary mirrors is all less than λ/30. The optical system's maximum field of view (1,- 1)RMS at low temperatures is 0.2840λ, while the minimum field of view (-1,1)RMS is 0.1549λ, both satisfying the requirements of the low-temperature collimation system. The adaptability of the collimation system at low temperatures and the feasibility of the athermal structure design are confirmed through thermal-structural-optical integrated simulation analysis.

In recent years, the rapid development of nuclear industry has accumulated a large number of radioactive waste, and it is still increasing year by year. At present, the most reasonable way is to cure the radioactive waste for glass first, and then put it into deep underground storage for storage. But there are several mainstream glass curing methods have some problems, so a fast and efficient treatment method is particularly important. In this article, a method of glass curing using ultra-high power laser is proposed. In this article, the borosilicate glass curing body was successfully prepared by using laser, and no simulated analog oxide crystals were precipitated, which preliminarily verified the potential application value of laser sintering in radioactive waste treatment.

In this paper, a fiber-coupled module based on a TO-can green LD single-tube light source is designed. The module adopts the fast and slow axis collimation method, to obtain the fast and slow axis beam quality close to the near-circular collimated light, LD hexagonal stacking mode arrangement, the design of the reflecting prisms with parallel flat plate and light wedge beam shrinking device for the beam of the spatial density row, effectively reducing the "dead zone", so as to take full advantage of the optical fiber numerical aperture to improve the output brightness of the fiber coupling. The output brightness of the fiber coupling is improved. The simulation verifies that 19 green LDs with a power of 1.65W are coupled into a fiber with a numerical aperture of 0.22 and a core diameter of 50μm, with an output power of 30.08W, a fiber coupling efficiency of 97.63%, a corresponding luminance of 10.08MW/(cm2·Sr), and a total optical-optical transmission efficiency of the system of 95.95%.

The impact of environmental factors on water quality analysis has always been an important topic in scientific research. Among these factors, temperature is considered one of the key factors that may influence the determination of total nitrogen levels. This study focuses on seawater as the research object and aims to reduce the influence of temperature variations in marine environments on the measurements of an in-situ total nitrogen analyzer. Different environmental water temperatures were collected for the total nitrogen analyzer's measurement data using standard samples. The collected data was then processed using curve plots and regression analysis to establish a linear regression model for thein-situ total nitrogen analyzer. The experiment revealed that as the temperature increases, the absorbance values measured by the total nitrogen analyzer show a decreasing trend, which may lead to underestimated total nitrogen measurements. The results indicate that high temperatures can affect the stability of reagents and the chemical reactions inside the analyzer, thus affecting the measurement results. Based on these findings, a temperature correction model was introduced in this study. This study introduced a temperature correction model. The optimized method effectively reduced the impact of temperature on in-situ total nitrogen analyzer determination, thereby enhancing the accuracy and stability of measurements.

In this paper, hydrophilicity after nanosecond pulsed laser cleaning of lubricating oil on the surface of DC04 steel was investigated. Influencing parameters of temperature field distribution and ablation depth on laser cleaned steel surface were simulated by using COMSOL Multiphysics software; The results show that when the average laser power is 50 W, the ablation depth of the steel surface gradually increases with the decrease of the laser scanning speed, and the increase of the ablation depth leads to the decrease of the contact angle of the steel surface. Subsequently, an experimental study of nanosecond pulsed laser cleaning of DC04 steel surfaces was carried out. The results show that the contact angle of the steel surface shows a tendency of decreasing and then increasing with the increase of the laser scanning speed. When the average laser power was 50W, the scanning pitch was 0.03mm and the scanning speed was 500mm/s, the lubricant on the steel surface was cleaned and had the best hydrophilicity on the surface. The static contact angle of the steel surface changed from the original 84° to 18°.

The stacking configuration of multilayers in van der Waals materials is a brand-new degree of freedom to tune the optical and electronic properties of two-dimensional materials. Here, the natural 3R-stacked MoS₂ was synthesized via chemical vapor transport (CVT) method. The mobility of bilayer reaches as high as 8.6 cm² V^-1 s^-1. The field-effect transistor (FET) demonstrates a current on/off ratio over 10⁸ and a sharp subthreshold swing (SS) value of 69 mV per dec. The 3R-stacked MoS₂ will be an excellent candidate for the application of electronic device.

This manuscript designs a compact LD single emitter end-pumped 1319 nm vortex laser. In order to compress the divergence angle and meet the requirements of compact design, a fast-axis and slow-axis integrated collimating lens was designed, with X and Y divergence angles of 1.87° and 0.99° after collimation. On this basis, a hollow pump beam was obtained by using a plano-convex lens and an axicon-lens. By simulating the pump beam at different angles of the axicon-lens, an ideal hollow pump light was obtained by using an axicon-lens with a cone angle of 20°. A bonded crystal of Nd: YAG and V: YAG was used, which utilizes selective dielectric coatings on the crystal end facets to suppress laser oscillation at 1064 nm and 1338 nm, and 1319 nm laser can be obtained. Subsequently, the heat dissipation structure for the pump module and the bonded crystal module was designed and the feasibility of the heat dissipation model was verified through ANSYS simulation.

With the advancement of analytical technology and chromatographic technology, abundant research results have been obtained in the preparation and improvement of gas chromatographic columns. The development of microelectromechanical system (MEMS) technology provides an effective processing technology for the manufacture of micro gas chromatographic column chips. This paper reviews the improvement of different types of gas chromatography columns, including large diameter, thick liquid film, micro-packed, cluster, annular and fiber-packed columns, etc., as well as the research progress of micro gas chromatography column chips based on MEMS technology. Such as microchannel processing technology, column structure, chip substrate material and preparation method of stationary phase. These advances provide an effective way to obtain micro-GC column chips with better separation performance.

The core device of inertial confinement fusion is a beam-target coupling instrument. The instrument has four orthographic cameras. And the camera is in a conjugate relationship with the target relative to the mirror. The existence of various errors leads to changes in the orthogonal relationship and conjugate relationship. Thus affecting the efficiency of inertial confinement fusion. In this paper, based on multi-body kinematics and homogeneous coordinate transformation theory, an error transfer model for beam-target coupled instruments is derived. The relationship between various errors and the final position of the camera is established. Build 3D model of beam-target coupling instrument by Creo. Through ANSYS Workbench, statically solve the assembly model of typical working conditions, obtain its deformation cloud image, and obtain the deformation data introduced by gravity. The motion error is measured by a biaxial autocollimator, the error is modeled by least square regression, and the parameters of the error transfer model are determined. The method in this paper effectively reduces the error introduced by gravity from 148 μm to 4 6.04 x 10^-4 μm. Another error introduced during movement has been reduced from 25.9 μm to 1.9 μm .The error compensation for the beam-target coupling instrument is realized

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