A design approach based on multi-objective genetic algorithms (MOGAs) is proposed for the aperiodic multilayer design of an X-ray supermirror. Based on the nondominated solutions obtained through MOGA, the turning points between average reflectivity and flatness are identified. In the solution areas around these turning points, the design method based on MOGAs with an angle-based preference selection mechanism (MOGA-ANGLE) is employed to further explore the designed solutions, and an optimized solution has been obtained. Compared with the multilayer design method based on genetic algorithm, the experimental results demonstrate that the multilayer design obtained by our approach has higher flatness and stronger robustness, and the potential performances have been fully explored.

Photovoltaic device based on van der Waals heterojunction provides an effective way to develop high-performance, low-power consumption, ultra-integrated micro photodetection system. In this paper, we construct an asymmetric Au/MoS2 Schottky junction to realize a planar MoS2-based photovoltaic device. In order to further improve the photoelectric performance of the device, we design a structure covering MoO3 on the surface of MoS2 to construct the heterojunction. Owing to the absorption properties of MoO3 in visible light and the excellent light transmittance of the ultra-thin two-dimensional structure, the electrons involved in conducting in MoS2 material are increased. In most of previous reports, the preparation methods and performance improvement of MoS2/MoO3 heterojunctions were the focus of research, but little attention was paid to exploring the influence of overlayer on devices. Therefore, in this work, we investigate the influence of overlayer thickness on device performance. With the help of atomic layer deposition (ALD) method to control the film thickness, each of the MoO3 materials with thickness of 4 nm, 12 nm and 20 nm (deposition periods of 10, 30 and 50, respectively) is covered on the surface of a MoS2-based photodetector. The photoelectric performance enhancement effects of three groups of heterojunction photodetectors are compared with each other. The results show that the thinner the MoO3 layer, the more significant the enhancement effect of heterojunction photodetectors is. This is mainly attributed to the fact that ultra-thin MoO3 layer not only has visible light absorption, but also reduces the influence of the covering layer on the light absorption of MoS2, thus achieving a heterojunction system with high light absorption efficiency. In addition, the interfacial electric field of the heterojunction effectively promotes the separation of photogenerated carriers, and the thinner the MoO3 coating layer, the weaker the effect of introducing the interfacial defects of the heterojunction is. Therefore, the dark current gain effect of the device is effectively suppressed, which is beneficial to improving the response speed and optical detectivity of the device. Comparing with pure MoS2 photovoltaic photodetectors, the photoresponsivity of MoS2/MoO3 heterojunction device in this paper is enhanced nearly 10 times. The device exhibits a high photoresponse of ~916.121 A/W, a detectivity of ~2.74×1011 Jones, and a fast response time of ~73 μs, showing that this design can effectively solve the low-responsiveness problem of planar photovoltaic device. In this study, for the first time, we construct a planar photovoltaic device based on MoS2/MoO3. By designing heterostructure and optimizing the thickness of the overlayer, the photoelectric performance of planar MoS2-based photovoltaic device is successfully improved, which provides a reference scheme for developing high-performance heterojunction photodetectors of MoS2/oxide materials in future.

Photovoltaic device based on van der Waals heterojunction provides an effective way to develop highperformance, low-power consumption, ultra-integrated micro photodetection system. In this paper, we construct an asymmetric Au/MoS2 Schottky junction to realize a planar MoS2-based photovoltaic device. In order to further improve the photoelectric performance of the device, we design a structure covering MoO3 on the surface of MoS2 to construct the heterojunction. Owing to the absorption properties of MoO3 in visible light and the excellent light transmittance of the ultra-thin two-dimensional structure, the electrons involved in conducting in MoS2 material are increased. In most of previous reports, the preparation methods and performance improvement of MoS2/MoO3 heterojunctions were the focus of research, but little attention was paid to exploring the influence of overlayer on devices. Therefore, in this work, we investigate the influence of overlayer thickness on device performance. With the help of atomic layer deposition (ALD) method to control the film thickness, each of the MoO3 materials with thickness of 4 nm, 12 nm and 20 nm (deposition periods of 10, 30 and 50, respectively) is covered on the surface of a MoS2-based photodetector. The photoelectric performance enhancement effects of three groups of heterojunction photodetectors are compared with each other. The results show that the thinner the MoO3 layer, the more significant the enhancement effect of heterojunction photodetectors is. This is mainly attributed to the fact that ultra-thin MoO3 layer not only has visible light absorption, but also reduces the influence of the covering layer on the light absorption of MoS2, thus achieving a heterojunction system with high light absorption efficiency. In addition, the interfacial electric field of the heterojunction effectively promotes the separation of photogenerated carriers, and the thinner the MoO3 coating layer, the weaker the effect of introducing the interfacial defects of the heterojunction is. Therefore, the dark current gain effect of the device is effectively suppressed, which is beneficial to improving the response speed and optical detectivity of the device. Comparing with pure MoS2 photovoltaic photodetectors, the photoresponsivity of MoS2/MoO3 heterojunction device in this paper is enhanced nearly 10 times. The device exhibits a high photoresponse of-916.121 A/W, a detectivity of-2.74x1011 Jones, and a fast response time of-73 & mu;s, showing that this design can effectively solve the low-responsiveness problem of planar photovoltaic device. In this study, for the first time, we construct a planar photovoltaic device based on MoS2/MoO3. By designing heterostructure and optimizing the thickness of the overlayer, the photoelectric performance of planar MoS2-based photovoltaic device is successfully improved, which provides a reference scheme for developing highperformance heterojunction photodetectors of MoS2/oxide materials in future.

The dynamic equation of the semiconductor laser system is a critical theoretical basis for investigating chaotic lasers, whose calculation accuracy directly determines the simulation reliability of the chaotic laser generated by the system. In this study, different semiconductor laser systems are evaluated and compared based on the two widely used methods of photoelectric field decomposition: amplitude-phase decomposition and real-imaginary part solution. The comparison shows that the computational results of both methods have a minimal difference in the case of low complexity of output light, but a significant difference exists in the case of high complexity. Furthermore, the numerical simulation of the photoelectric field using the real-imaginary part solution has higher precision and is more suitable than the amplitude-phase decomposition for analyzing semiconductor laser systems that generate chaotic lasers with higher complexity.

We investigated the frequency bandwidth, autocorrelation function, and complexity of chaotic temporal waveforms in unidirectionally coupled semiconductor lasers with time-delayed optical feedback. The effective bandwidth, peak value of autocorrelation function, and maximum Lyapunov exponent were simultaneously optimized by searching several control parameters of the laser systems based on multiobjective genetic algorithms. We found a conflicting relation between the effective bandwidth enhancement and the time-delay signature suppression, and a detailed relationship between the maximum Lyapunov exponent and the peak value of autocorrelation function.

With the purpose of designing the extreme ultraviolet polarizer with many objectives,a combined application of multi-objective genetic algorithms is theoretically proposed.Owing to the multi-objective genetic algorithm,the relationships between different designing objectives of extreme ultraviolet polarizer have been obtained by analyzing the distribution of nondominated solutions in the four-dimensional objective space,and the optimized multilayer design can be obtained by guiding the searching in the desired region based on the multi-objective genetic algorithm with reference direction.Compared with the conventional method of multilayer design,our method has a higher probability of achieving the optimal multilayer design.Our work should be the first research in optimizing the optical multilayer designs in the high-dimensional objective space,and our results demonstrate a potential application of our method in the designs of optical thin films.

为降低X射线超反射镜镀膜误差导致的光谱性能退化、提高其可制备性,提出了基于多目标遗传算法的X射线超反射镜鲁棒性设计方法,将X射线超反射镜的反射带性能和膜厚随机误差引起的反射带偏差作为两个优化目标进行优化.考虑到X射线光学系统掠入射反射的特殊性,在优化求解的计算过程中加入了入射光发散角对多层膜反射率的影响,进而分别设计了具有掠入射角度带宽和能量带宽的两种X射线多层膜反射镜鲁棒性膜系.结果表明,相比只优化光学性能的传统优化设计方法,鲁棒性设计方法能够得到反射性能良好且对膜厚随机误差不敏感的超反射镜膜系设计.

Chaotic lasers are widely used in secure communication, lidar, optical detection and other applications due to their noise-like randomness, excellent anti-interference and other advantages. Moreover, as semiconductor lasers have small size, stable structure and other advantages, it has become one of the main lasers to produce optical chaos. However, the chaotic laser output from conventional optical feedback semiconductor lasers has the problems of narrow signal bandwidth and delay characteristics, which seriously affect their applications. With consideration for these problems, a comprehensive introduction to reduce the delay characteristics and optimize the chaotic laser bandwidth are reviewed based on recent literatures. This paper also summarizes the research progresses of chaotic secret communication, which is very important in the synchronization of chaotic lasers. The chaotic output of semiconductor lasers and the applications of chaotic lasers are also summarized, and then their development and potential future applications are discussed.

At the beginning of August 2017, Netherlands reported that a wide range of eggs were contaminated with the insecticide fipronil. In this study, the Raman spectroscopy was used to solve the problem of fipronil detection. The stable configuration and all vibration modes of the molecule were obtained after the geometrical structure optimization and frequency calculation, and the theoretical Raman Scattering spectroscopy of the stable configuration of fipronil was also calculated. Normal Raman spectroscopy and surface enhanced Raman spectroscopy of fipronil were collected by HORIBA's T64000 grating confocal micro-Raman spectroscopy and Ag/Cu nano-substrate. The strong peaks appeared at 211, 308, 350, 867, 1 323, 1 432 cm(-1), and the substrong peak appeared at 254, 407, 443, 463, 511, 607, 646, 712, 800, 1065, 1639 cm(-1). The results show that the theoretically calculated vibration frequency agrees well with the experimental measurements at all strong peaks and most sub-strong peaks. The vibration modes corresponding to the frequencies of the fipronil molecule in the range of 200 similar to 2 000 cm(-1) were assigned. The six strong peaks arranged from small to large were judged to be 21H-22H torsional vibration, 10E-11F deformation vibration, 21H-22H out-of-plane torsional vibration, 15N-22H twisting vibration, 6C stretching vibration and 21H in-plane torsional vibration, benzene ring breathing vibration and stretching vibration of 9C, 7H-8H in-plane torsional vibration. It was found that the surface-enhanced Raman spectrum has a slight frequency shift with respect to the Raman spectrum. The peaks at 211, 867, 1400, and 1 432 cm(-1) in the surface-enhanced Raman spectroscopy were selectively enhanced. According to the selection rule of surface-enhanced Raman spectroscopy, it is interpreted as the atom corresponding to the relevant vibration peak and the surface of the silver substrate may be in a nearly vertical state and may be stick to the silver surface. In the next step, fipronil will be planned to be mixed into eggs, and the identification of fipronil in different concentrations in eggs will be carried out. The results of the study can provide a theoretical basis for the Raman spectroscopy of fipronil, which will promote the rapid detection and on-line detection of fipronil residues in food and agricultural products. Raman spectroscopy will be used as a supplement to conventional chemical detection methods.

文章对长春理工大学理学院近4年的本科光学课程教学改革实践进行了总结,探讨分析其在教学内容、教学方法和教学手段方面的经验,为进一步深化光学教学改革和提高教学质量积累经验和提供参考.

科研水平是高等院校的教育教学水平、科技创新能力、学生创新能力、学生乃至教师的创业能力的重要标志.高等院校教育与基础学校教育的重要区别在于创新型人才的培养,而本科生参与科研的范围和深度决定着创新型人才培养的质量.高等学校可通过多类型导师相配合、学校提供政策及基金支撑,逐步增加并提高科研导师的地位,促使本科生导师制在提高我国高等院校创新创业教育水平中发挥重要的作用.

极紫外多层膜利用各个界面反射光的相长干涉,在极紫外波段获得了高反射率,已成为极紫外光刻设备中反射式光学系统的核心元件.本文对近年来极紫外多层膜表征、设计和制备领域的研究现状进行了介绍和分析.由于多层膜的光学性能易受膜层界面粗糙度、膜层扩散以及膜厚误差等因素的影响,文中重点对联合多检测技术的多层膜表征、膜系优化算法和膜层界面优化工程进行阐述.除此之外,本文针对联合多项检测技术表征以及鲁棒性膜系设计,讨论了多目标优化算法在极紫外多层膜技术中的应用潜力,展望了多层膜技术在软X射线波段及光谱裁剪等领域的应用.

The chicken and skin were studied by fluorescence spectroscopy. The three-dimensional fluorescence spectra of chicken and skin were measured, It was concluded that the optimal excitation wavelength corresponding to the fluorescence peak of 330 nm in chicken was 270 nm, and that of 475 nm and 520 nm was 370 nm. The optimal excitation wavelength corresponding to the 475 nm fluorescence peak of chicken skin was 370 nm. The fluorescence spectra of chicken skin and chicken excited by the wavelength of 370 nm were analyzed. The fluorescence peak came from myoglobin at 555 nm at the beginning of roasting, and the contribution of fluorescence peak came from oxygenated myoglobin at 540 nm and 580 nm as the baking time increased. When the baking time was more than 12 min, the fluorescence intensity of oxygenated myoglobin at 580 nm was close to zero. At this point, a considerable part of myoglobin had been converted into ferric myoglobin, while Fe3+ in ferric myoglobin could not be absorbed by human body. At this point, the skin of chicken was no longer suitable for large amounts of consumption, while the relative performance of chicken was not obvious.

In order to design broadband extreme ultraviolet multilayers with many objectives, the multiobjective genetic algorithm and the multiobjective genetics algorithm with reference direction have been improved and combined used. The certain conflicting relations between three primary design objectives have been obtained by analyzing the distribution of nondominated solutions, and the multilayer designs with critical average reflectivities have been found. Basing on the multiobjective genetics algorithm with reference direction, the exact multilayer design has been obtained by guiding the searching in desired region of solution space. Our method can supply the multilayer designs which are the optimal trade-offs among these design objectives, and it has a great potential in designing optical multilayers with more objectives.

The random layer thickness variations can induce a great deformation of the experimental reflection of broadband extreme ultraviolet multilayer. In order to reduce this influence of random layer thickness fluctuations, the multiobjective genetic algorithm has been improved and used in the robust design of multilayer with a broad angular bandpass. The robust multilayer with a lower sensitivity to random thickness errors have been obtained and the corresponding multilayer mirrors were fabricated. The experimental results of robust Mo/Si multilayer with a wide angular band were presented and analyzed, and the advantage of robust multilayer design was demonstrated.

用荧光光谱法和拉曼光谱法对香皂中荧光增白剂进行了定性测量.对常见的19个品牌不同系列共46种香皂和8种荧光增白剂进行研究.逐一对样品进行荧光光谱及拉曼光谱的检测,根据光谱检测结果分析香皂样品是否含有荧光增白剂及其荧光增白剂种类.研究结果表明8种香皂含荧光增白剂,7种包装成分表中有标注,但有6种不准确,1种并未标注其含有荧光增白剂成分.

掠入射X射线反射(GIXR)是光学薄膜表征的优选方法,但它需要建立相应的物理模型并采用一定的算法进行拟合求解.针对目前普遍使用的进化算法存在着种群规模大、收敛速度慢和拟合精度差的问题,本文将云模型与量子进化算法相结合,提出了一种基于云模型量子进化算法(CQEA)的薄膜微观结构表征方法,并将该算法应用于Si单层膜和周期极紫外Mo/Si多层膜的表征之中,并将其拟合结果与基于进化算法的拟合结果进行对比.分析表明,CQEA具有种群规模小、收敛速度快和拟合精度高的优势,同时给出的薄膜结构参数值精度更高.相关研究工作体现了CQEA应用于薄膜微观结构表征中的可行性与优越性,为基于GIXR的薄膜微观结构表征提供一种更优选的拟合求解方法.

极紫外(EUV)宽带多层膜的光谱性能对膜厚控制精度要求较高,仅由时间控制膜厚的镀膜系统难以满足其精度控制要求.本文提出了基于进化算法的宽带EUV多层膜离散化膜系设计方法,与传统膜系设计相比,离散化膜系所制备多层膜具有更为优良的EUV反射光谱性能.为验证离散化膜系设计在宽带EUV多层膜研制中的优越性,采用磁控溅射方法对具有离散化膜系的宽带多层膜反射镜进行了制备和测试.测试结果表明:研制的宽角度多层膜反射镜可实现入射角带宽为0°～17°,高于41％的反射率;研制的堆栈宽角度多层膜反射镜可实现入射角带宽为0°～18.5°,高于35％的反射率;研制的宽光谱多层膜反射镜可实现波长带宽为12.9～14.9 nm,高于21％的反射率.

Considering the random fluctuations of the layer thickness, a method of robust design of broadband EUV multilayers based on multi-objective evolutionary algorithm is presented. Owing to the optimization of multi-objective evolutionary algorithm, the optical performance and robust quality of broadband Mo/Si multilayer can be optimized simultaneously, and then a set of robust designs of aperiodic EUV multilayers, which are insensitive to the thickness errors can be obtained in one single simulation run. The robust designs of broadband Mo/Si multilayers could be used to reduce the production risks of EUV mirrors, and this research demonstrates a great potential of application of multi-objective evolutionary algorithm on the design of optical thin film.

在以培养具有完整物理知识体系的理科本科生的教学目标中,热学教学是必要的组成部分.为了深化热学教学内容并提高教学质量,在教学过程中结合相关史实并融入唯物辩证法的相关理论是非常有效和必要的.结合唯物辩证法的热学教学方法不仅可以激发学生的学习兴趣,还可以促进学生对相关知识的理解,同时还有助于培养学生树立正确的世界观,提高学生的人文素养,进而实现培养创新型高素质人才的教学目的.