In recent years, the propagation properties of various types of beams in media have attracted much attention, especially Pearcey-Gaussian beams, which have become a research hotspot due to their unique properties, such as self-focusing and self-healing. However, although the propagation behavior of Pearcey-Gaussian beams in different potentials, such as linear and parabolic potentials, has been investigated, its propagation characteristics in Gaussian potentials are still understudied. In particular, there has yet to be a systematic discussion on how to control the dynamics behavior of the beam by adjusting the parameters of the Gaussian potential. This paper adopts the stepwise Fourier method to study the propagation characteristics of a Pearcey-Gaussian beam in a nonlinear medium with Gaussian potential. The results show that modulation strength P, potential center position x0, potential width d0, truncation coefficient sigma, and integral term coefficient a significantly influence the propagation properties of the Pearcey-Gaussian beam. By adjusting these parameters, the peak intensity, the period distance, and the propagation path of the beam can be precisely controlled, which provides a solid theoretical foundation and experimental guidance for optimizing the dynamic control of the beam.

initial parameters of Airyprime pulses determine how they evolve over time and across frequencies. A smaller truncation coefficient results in higher side-lobe energy, creating a broader and flatter supercontinuum (SC). In contrast, a larger truncation coefficient reduces side-lobe energy, narrowing the spectrum. A negative initial chirp compresses the main lobe in time and flattens the spectrum, while a positive chirp causes temporal broadening. Higher peak powers increase nonlinear effects, further broadening the SC. Propagation in fiber with two zero-dispersion wavelengths (ZDWs) emits both blue-shifted and red-shifted dispersive waves (DWs), extending the spectral bandwidth. Compared to conventional Airy pulses, Airyprime pulses produce temporally compact, robust profiles and flatter, more uniform SC spectra. This highlights their strong potential for next-generation ultra-wideband light sources.

In recent years, Pearcey-Gaussian (PG) beams have attracted much attention in optics due to their unique properties, such as self-flip, self-focusing, self-healing, and asymmetric trailing. However, studies on the evolutionary properties of this beam in nonlocal media still need to be improved, limiting the comprehensive understanding of its transport behavior. In this paper, the spatial and frequency domain evolution of the trailing-leading PG beam and the trailing-lagging PG- beam in nonlocal media are investigated in depth. The effects of the parameters of the nonlocal media (nonlinear coefficients N and characteristic width sigma) and the initial parameter of the PG beams (truncation coefficients a) on the evolution characteristics are explored. The results show that the nonlinear coefficient N, the characteristic width sigma, and the truncation coefficient a significantly affect the peak energy of the primary flap, the intensity of the sidelobe, and its deflection angle in the spatial domain of the beam. The study then compares the propagation evolution of solitons, Airy beams, and PG beams in nonlocal media, finding that the PG beam exhibits a noticeable linear deflection to the right in the spatial domain, while the spectrum's central position remains stable without significant changes. Finally, the period and peak power variations of breathers formed by PG+ beam in nonlocal media are investigated. The results provide a necessary theoretical basis for manipulating beams in nonlocal media.

A high-sensitivity terahertz (THz) biosensor is proposed in this paper based on a multi-layer hybrid structure consisting of a defect mode and graphene with a truncation layer. This biosensor is based on symmetrical Bragg reflectors with a defect layer and graphene with a truncation layer, which effectively comprise a multi-layer hybrid resonance excitation structure. The high sensitivity of this biosensor is developed through defect mode resonance, and the resonance reflection peak is made sharper and more sensitive by using graphene with a truncation layer. After testing and analysis, the sensitivity of this biosensor structure is greatly affected by the refractive index and thickness of the sensing medium. By setting parameters appropriately, the composite structure can be used as both a liquid biosensor and a gas biosensor, the maximum sensitivity of which can surpass 2000°/RIU, while an FOM value of 22,500 RIU−1 can be achieved. At the same time, when the refractive index of the liquid sensing medium changes to 0.01 relative to water (the same applies to changes in the gas sensing medium), the sensitivity of this structure still exceeds 600°/RIU, demonstrating that this biosensor has advantages including high sensitivity, a high FOM, wide applicability, and slow sensitivity attenuation. Therefore, the sensing scheme proposed in this paper has potential application prospects in the field of biosensing based on micro/nanostructures due to its simple structure, low requirements for processing conditions, and high sensitivity.

Nickel diselenide (NiSe2) microspheres were synthesized using a chemical vapor deposition (CVD) method, and their nonlinear optical properties were investigated. The prepared NiSe2 exhibits good nonlinear characteristics, demonstrating a high modulation depth and a low saturation intensity. Then the NiSe2 was used as a saturable absorber device and integrated into a 1.5 μm erbium-doped fiber laser to generate Q-switched pulse. By optimizing the cavity dispersion and adjusting the polarization state within the cavity, the single pulse tunable Q-switched pulse, Q-switched mode-locking pulse and quasi-mode-locked pulse based on NiSe2 saturable absorber are realized. Among them, the signal-to-noise ratio of the quasi-mode-locked pulse is as high as 68 dB, which proves that the resulting pulse has high stability. The findings of this study suggest that NiSe2 SA devices have the potential to be developed as highly efficient candidates for ultrafast photonics and can find extensive applications in nonlinear optical fields.

This paper investigates the propagation characteristics of chirped Pierce-Gaussian beams in both free space and PT-symmetric media using the stepwise Fourier method. An in-depth analysis is conducted on the effects of the truncation factor, chirp factor, modulation depth, and gain/loss coefficient of the medium. When the wave propagates in free space, the truncation factor modulates its focusing intensity, and the initial chirp controls the direction of beam deflection. Conversely, when propagated via a PT-symmetric medium, the Pierce-Gaussian beam emits a soliton at the focal point and attains reliable propagation. The modulation strength P and gain/loss coefficient W 0 of the PT-symmetric medium impact the shedding soliton's peak intensity and oscillation period. Meanwhile, the beam's initial chirp parameter c can regulate the peak intensity of the shedding soliton. The results of this study offer a significant theoretical foundation for understanding the dynamics of the propagation of specialized beams.

The supercontinuum generation and manipulation of Airy-Gaussian pulses in a photonic crystal fiber with three zero-dispersion points are studied using the split-step Fourier method. Firstly, the spectral evolution of Airy-Gaussian pulses in four photonic crystal fibers with different barrier widths was discussed, and the optimal fiber was determined after considering the factors of width and flatness. By analyzing the mechanism of supercontinuum generation in photonic crystal fibers with single, double and three zero-dispersion points, it is found that the photonic crystal fiber with three zero-dispersion points have a larger spectral width due to the component of tunneling solitons. Then, the effects of four characteristic parameters (truncation factor a, distribution factor χ0, initial chirp C and central wavelength λ) on forming the supercontinuum spectrum of Airy-Gaussian pulses are analyzed in detail. The results show that the spectral width and energy intensity of the dispersive wave and tunneling soliton generation can be well controlled by adjusting the barrier width and initial parameters of the pulse. These research results provide a theoretical basis for generating and manipulating high-power mid-infrared supercontinuum sources.

针对环境消毒问题,设计了一款基于STM 32 单片机的智能消毒机器人.该机器人主要由电机驱动模块、稳压电源模块、超声波避障模块及OpenMV机器视觉模块等组成,能够实现智能识别、自动避障的自主移动式消毒功能.采用PID算法,对智能消毒机器人的控制系统进行调节,可实现移动平稳功能.测试结果表明,该智能消毒机器人实现了预期的设计功能,为环境消毒问题提供了更有效的解决方法,具有良好的应用前景.

In this study, the propagation and control of Airy-Gaussian beams in Gaussian parity-time ( PT) symmetric media are investigated numerically, by utilizing the nonlinear Schrodinger equation as a theoretical model. The impacts of the characteristic parameters of Gaussian PT symmetric media ( modulation depth P, modulation factor omega, and gain/loss factor W (0)) and the characteristic parameters of Airy- Gaussian beams (truncation factor alpha, distribution factor chi(0)) on propagation characteristics of Airy-Gaussian beams are examined in detail. The results demonstrate that the Airy- Gaussian beams can produce oscillating solitons and transmit steadily in Gaussian PT symmetric media. The soliton strength increases with the increase of P, W-0, and a, and decreases with the increase of omega The oscillation period decreases with the increase of P and. and increases with the increase of W0. When.0 increases, when 0 0. 55, the peak intensity of the soliton decreases rapidly. This research can offer a theoretical foundation for the use of soliton transmission in complicated heterogeneous media and all-optical control

The propagation characteristics of Airy beams in an inhomogeneous medium with periodic potential are studied theoretically and numerically. The Gross–Pitaevskii equation was solved with periodic potential using the separating variables method, and a breathing soliton solution and the breathing period were obtained. Further, the propagation properties of an Airy beam, and the interaction between two Airy beams while considering the medium parameters and beam parameters were numerically simulated in detail. First, we discuss the influence of the initial medium parameters (modulation intensity P and modulation frequency ω) on the propagation characteristics. Then, we investigate the effect of the initial beam parameters (initial chirp C and position x0) on the propagation characteristics. Lastly, the interaction of two Airy beams with opposite spatial positions for different phase φ, amplitude A, and initial interval x0 is analyzed. The breathing period and central position of the breathing solitons could be controlled by changing the initial medium parameters. By varying the initial beam parameters, the deflection direction and size, and the maximal intensity of the breathing solitons were manipulated. The breathing solitons of different bound states were formed by changing the phase φ, amplitude A, and initial interval x0 of two Airy beams. The results provide a theoretical basis for the propagation and manipulation of Airy beams.

The evolution of Cos−Gaussian beams in periodic potential optical lattices is theoretically and numerically investigated. By theoretical analysis, a breathing soliton solution of the Gross–Pitaevskii equation with periodic potential is obtained, and the period of the breathing soliton is solved. In addition, the evolution of Cos−Gaussian beams in periodic potential optical lattices is numerically simulated. It is found that breathing solitons generate by appropriately choosing initial medium and beam parameters. Firstly, the effects of the initial parameters of Cos−Gaussian beams (initial phase and width) on its initial waveform and the propagation characteristics of breathing soliton are discussed in detail. Then, the influence of the initial parameters (modulation intensity and modulation frequency) of a photonic lattice on the propagation characteristics of breathing solitons is investigated. Finally, the effects of modulation intensity and modulation frequency on the width and period of the breathing soliton are analyzed. The results show that the number of breathing solitons is manipulated by controlling the initial parameters of Cos−Gaussian beams. The period and width of a breathing soliton are controlled by manipulating the initial parameters of a periodic photonic lattice. The results provide some theoretical basis for the generation and manipulation of breathing solitons.

结合分步傅里叶方法和四阶Runge-Kutta积分法，研究了有限能量cosh-Airy脉冲在双零色散介质中的超连续谱产生与操控。首先，详细讨论了特征参数截断系数a、初始啁啾C和分布因子χ 0 对cosh-Airy脉冲在双零色散介质中的演化影响，并统计了a、C和χ 0 对超连续谱宽度的影响。然后，进一步研究了高阶非线性效应对cosh-Airy脉冲产生超连续谱的影响。结果表明：通过操控coshAiry脉冲的特征参数可以控制超连续谱的宽度；当存在高阶非线性效应时，超连续谱的平坦性会受到影响。研究结果为超连续谱的产生和操控以及宽带激光光源提供一些理论基础。

工程教育认证对促进电子信息工程专业教育改革和发展具有重要的理论意义和实践意义.为了进一步提高应用型人才培养质量,立足工程教育认证标准,文章首先介绍了基于OBE理念的电子信息工程专业课程体系构建流程,然后探索了工程实践类课程体系构建思路,最后阐述了湖南城市学院电子信息工程专业在工程实践类课程体系优化方面的举措,旨在为应用型本科院校的其他工科专业开展工程教育认证的课程体系构建提供参考.

We numerically investigate the evolution of Airy-Gaussian (AiG) pulses in photonic crystal fiber with two zero-dispersion wavelengths. Firstly, in the absence of higher-order nonlinear effects, the effects of three essential parameters of AiG pulses (truncation coefficient, distribution factor, and initial chirp) on the pulse evolution are studied in detail. The results indicate that initial AiG pump pulses with a small truncation coefficient, small distribution factor, and positive chirp are beneficial for obtaining a wider supercontinuum spectrum. Moreover, we further take stimulated Raman scattering (SRS) and self-steepening (SS) effects into account, and find that SRS greatly broadens the output spectrum when AiG pulses with a small distribution factor (chi(0) = 0.1), however, it also leads to obvious spectrum collapse and the collapse will be reduced to a certain extent due to SS.

Abstract We numerically investigate and statistically analyze the impact of medium parameters (modulation depth P, modulation factor ω, and gain/loss strength W 0) and beam parameters (truncation coefficient a and distribution factor χ 0) on the propagation characteristics of a cosh-Airy beam in the Gaussian parity-time (PT)-symmetric potential. It is demonstrated that the main lobe of a cosh-Airy beam is captured as a soliton, which varies periodically during propagation. The residual beam self-accelerates along a parabolic trajectory due to the self-healing property. With increment in P, the period of a trapped soliton decreases almost monotonically, while the peak power of a trapped soliton increases monotonically. With the increase in ω or decrease in the absolute value of W 0, the period and peak power of a trapped soliton decrease rapidly and then almost remain unchanged. Moreover, it is indicated that the period of a trapped soliton remains basically unchanged no matter a and χ 0 increase or decrease. The peak power of a trapped soliton increases with increment of a, but the peak power of a trapped soliton stays relatively constant irrespective of variation in χ 0.

基于微磁学理论和模拟研究电流驱动的斯格明子的移动特性.相对于纳米带,凹槽纳米带可提供更大的边缘排斥力抑制斯格明子横向移动,最大驱动电流(Jmax)和最大斯格明子移动速度(Vmax)显著增加.随着注入电流密度的增加,凹槽纳米带内斯格明子移动速度先增加到最大速度,而后减小或保持不变.通过增加边缘宽度或厚度,Jmax和Vmax线性增加.研究凹槽纳米带边缘厚度与宽度对斯格明子移动的调制规律,并基于微磁学理论对其进行解释.为基于纳米带结构的自旋电子器件的开发提供理论依据.

在超分辨荧光显微成像技术中,单分子定位显微方法是被广泛应用的技术之一.根据荧光显微成像原理构造多测量矢量压缩感知模型(Multiple Measurement Vector-Compressed Sensing,MMV-CS),并采用多重稀疏贝叶斯学习算法进行求解,来实现超分辨荧光图像重建.分析了有效像元大小、荧光分子生成的光子数和背景信号泊松化噪声对重建结果的影响,以及在图像进行分块处理时算法运行时间的分析.模拟和实验计算分析表明,当点扩展函数的标准差在160 nm时,有效像元大小在120、160、200 nm能取得较好的重构效果,而在60 nm时效果较差.探测器收集的光子数越多,重构效果越好,随着背景信号光子数增加时,离得越近的样品结构越不能分辨.在同样的分块处理情况下,MMV-CS比同伦算法(L1-Homotopy,L1-H)和凸优化算法(CVX)分别快一个数量级和三个数量级,因此,在研究三维超分辨荧光显微成像时,MMV-CS算法在运行时间上具有更大的优势.

Laser trimming has become one of the powerful tools for precise manufacturing of alloy resistors that are widely used in electrical vehicles, electrical controlling, and in appliances. In this work, the influence of femtosecond laser trimming is compared with nanosecond laser trimming. The authors found that lasers focused on different heights relative to the sample surface induced significant changes in surface morphologies. The resistance change was systematically investigated as a function of cutting lengths and cutting depths of different laser powers for both lasers. The experiments display that femtosecond laser trimming has a higher precision of the resistance adjustment than nanosecond laser trimming. The periodic ripple structure by the femtosecond laser was investigated at the focus position above, onto, or beneath the surface. The period of a low frequency ripple structure (LFRS) on the ablated groove bottom is about 600–700 nm when the laser focuses just right on the surface but changes to 490–560 nm when focusing above or beneath the surface. The period of a high frequency ripple structure is about 100–380 nm at the vertical direction of LFRS. The period of low frequency ripple on the outside of the groove is smaller than that on the groove bottom for all three focusing cases. The period of the LFRS is not sensitive to the laser power. The range of the resistor value change in the s-polarized light direction of the femtosecond laser is more than that in the p-polarized light direction.

Laser-based micro-to-nanomanufacturingMicro-to-nanomanufacturing becomes attractive in surface engineeringSurface engineering, precising machiningPrecising machining and 2D and 3D microprintingMicroprinting. This chapter introduces the fundamental of light-nanomaterial interactionLight-nanomaterial interaction, the size effectSize effect and scaling of nanomaterialsScaling of nanomaterials and the surface plasmonic excitationSurface plasmonic excitation of nanomaterialsNanomaterials. We focus on the unique features of energy and mass transportingMass transporting at a nanoscale under photonic excitationPhotonic excitation. For photonic manufacturingPhotonic manufacturing, we mainly compare the photothermal effectPhotothermal effect induced by long pulse (long than 1 picosecond) or continue wave laserContinue wave laser to the nonthermal effectNonthermal effect induced by an ultrafast pulsed laserUltrafast pulsed laser (shorter than 1 picoseconds). We review various laser-based processingLaser-based processing, such as, photonic reductionPhotonic reduction, sinteringSintering, laser direct writingLaser direct writing and laser carbonizationLaser carbonization. Subsequently we reviewed two kinds of key techniques for micro-to-nanomanufacturing: various micro-to-nano manipulationsMicro-to-nano manipulations and nanojoiningNanojoining. On the basis of these reviews, we introduce latest progresses on innovative molecular devicesMolecular devices, near-field manufacturingNear-field manufacturing and super-resolution manufacturingSuper-resolution manufacturing.

通信原理是通信、电子、信息处理等多个专业的重要专业核心课程,是学习电子信息类后续专业课程的基石.为了贯彻落实教育部在2018召开的新时代全国高等学校本科教育工作会议精神,在工程教育认证背景下,培养学生自然科学和工程基础在电子、通信系统的应用能力、设计能力和创新能力为根本目标,结合我校是地方应用型本科院校的实际情况,对通信原理课程教学进行一些探索改革,提高通信原理课程的教学效果.