Vectorial spin-orbital Hall effect of light upon tight focusing and its experimental observation in azopolymer films

Hall effect of light is a result of symmetry breaking in spin and/or orbital angular momentum(OAM)possessing optical system and is caused by e.g.refractive index gradient/interface between media or focusing of a spatially asymmetrical beam,similar to the electric field breaking the symmetry in spin Hall effect for electrons.The angular momentum(AM)conservation law in the ensuing asymmetric system dictates redistribution of spin and orbital angular momentum,and is manifested in spin-orbit,orbit-orbit,and orbit-spin conversions and reorganization,i.e.spin-orbit and orbit-orbit interaction.This AM restructuring in turn requires shifts of the barycenter of the electric field of light.In the present study we show,both analytically and by numerical simulation,how different electric field components are displaced upon tight focusing of an asymmetric light beam having OAM and spin.The relation between field components shifts and the AM components shifts/redistribution is presented too.Moreover,we experimentally demonstrate,for the first time,to the best of our knowledge,the spin-orbit Hall effect of light upon tight focusing in free space.This is achieved using azopolymers as a media detecting longitudinal or z component of the electrical field of light.These findings elucidate the Hall effect of light and may broaden the spectrum of its applications.

Effect Due to the Particle Nature of the Doppler Shifted Radiation on the Dynamics of the Spherical Light Emitting Source

The Doppler effect is a phenomenon of intrinsic kinematic character. This paper analyzes the kinematic Doppler effect for the case where the source is moving and the observer is at rest in the classical limit. The particle nature properties of radiation are considered and how it affects the dynamics of the Source has been studied. The dynamical and kinematical equations have been derived by considering this effect. It has been conclusively shown that a moving light-emitting source experiences a finite recoil momentum in the direction opposite to the direction of motion and come to rest in finite time.

Switching the direction of spin accumulation in the spin Hall effect of light by adjusting the optical axis of an uniaxial crystal

We theoretically and experimentally investigate a switchable spin Hall effect（SHE） of light in reflection near the Brewster angle at an air-uniaxial crystal interface.We find a large transverse spin splitting near the Brewster angle,whose sign can be altered by rotating the optical axis.As an analogy of the SHE in an electronic system,a switchable spin accumulation in the SHE of light is detected.We are able to switch the direction of the spin accumulation by adjusting the optical axis angle of the uniaxial crystal.These findings may give opportunities for photon spin manipulating and developing a new generation of nano-photonic devices.

Spin Hall effect of a light beam in anisotropic metamaterials

We theoretically investigate a switchable spin Hall effect of light （SHEL） in reflection for three specific dispersion relations at an air-anisotropic metamaterial interface. The displacements of horizontal and vertical polarization compo- nents vary with the incident angle at different dispersion relations. The transverse displacements can be obtained with the relevant metamaterial whose refractive index can be arbitrarily tailed. The results of the SHEL in the metamaterial provide a new way for manipulating the transverse displacements of a specific polarization component.

Angle Compensation and Asymmetry Effect of Light Diffracted by Millimeter Liquid Surface Slosh Wave

The angle compensation method is adopted to detect sloshing waves by laser diffraction, in the case that the wavelength of the sloshing waves is much greater than that of the incident light. The clear diffraction pattern is observed to be of asymmetry, involving orders, position and interval of the diffraction spots that are discovered during the light grazing incidence. It is found that the larger the angle of incidence is, the more obvious the asymmetry is. The higher the negative diffraction orders are, the smaller the intervals between spots are. On the contrary~ in the positive region, the higher the diffraction orders are, the larger the spot intervals are. The positive interval is larger than that of the same negative diffraction order. If the incident angle reaches 1.558 rad in the experiment, all positive diffraction orders completely vanish. Based on the mechanism of phase modulation and with the Fourier transform method, the relations between the incident angle and position, interval spaces, and orders of diffraction spots are derived theoretically. The theoretical calculations are compared with the experimental data, and the comparison shows that the theoretical calculations are in good agreement with the experimental measurement.

Localized Effect of Light Diffraction by Capillary Wave

The localized effect of light diffracted by a capillary wave is discovered by changing the wave amplitude. The localized range is related to the wave number and the amplitude. The dependence of the half maximum localized angle on the wave number and amplitude is analytically derived. Meanwhile, the analytic angular distribution of the diffraction light in the localized range is obtained. Experiments are carried out to achieve diffraction patterns to confirm the localized effect and to measure the angular distribution of the diffraction light intensity as well as to determine the localized range scales corresponding to different wave amplitudes. Theoretical curves of the light intensity angular distribution and localized interval widths related to surface acoustic wave amplitudes are compared with the experimental data. The experimental results agree well with the theoretical prediction.

Dynamical Casimir effect in superradiant light scattering by Bose Einstein condensate in an optomechanical cavity

We investigate the effects of dynamical Casimir effect in superradiant light scattering by Bose-Einstein condensate in an optomechanical cavity. The system is studied using both classical and quantized mirror motions. The cavity frequency is harmonically modulated in time for both the cases. The main quantity of interest is the number of intracavity scattered photons. The system has been investigated under the weak and strong modulations. It has been observed that the amplitude of the scattered photons is more for the classical mirror motion than the quantized mirror motion. Also, initially, the amplitude of scattered photons is high for lower modulation amplitude than higher modulation amplitude. We also found that the behavior of the plots are similar under strong and weak modulations for the quantized mirror motion.

Controlled LED Lighting for Horticulture: A Review

As energy gradually becomes a more valuable commodity, the desire for reduced energy losses strengthens. Lighting is a critical field on this matter, as it accounts for a large percentage of the global electricity consumption and modern lighting systems are greatly more efficient than incandescent, discharge, and fluorescent lights. Previous research has proven that plants do not require the entire visible spectrum but react only to specific wavelengths, making it possible to control their growth and yield via artificial lighting. The flexibility of control of Light Emitting Diode (LED) lights allows for the combination of great energy losses reduction and controlled plant growth, achieving the improvement of two major parameters in a single action. This review paper summarizes the current research on the effect different light wavelengths have on specific plant species and discusses the applications of LED lighting for horticulture, yield storage, and disease protection.

Nonlinear effect of the structured light profilometry in the phase-shifting method and error correction

Digital structured light （SL） profilometry is increasingly used in three-dimensional （3D） measurement technology. However, the nonlinearity of the off-the-shelf projectors and cameras seriously reduces the measurement accuracy. In this paper, first, we review the nonlinear effects of the projector-camera system in the phase-shifting structured light depth measurement method. We show that high order harmonic wave components lead to phase error in the phase-shifting method. Then a practical method based on frequency domain filtering is proposed for nonlinear error reduction. By using this method, the nonlinear calibration of the SL system is not required. Moreover, both the nonlinear effects of the projector and the camera can be effectively reduced. The simulations and experiments have verified our nonlinear correction method.

Effect of Ambient Humidity on the Transmission of UV/Visible Light through Model Human Epidermis

Transmission of light through model human epidermal samples is investigated at four different wavelengths and at varying ambient humidity. Light from light emitting diodes (LEDs) is used for transmission measurements through the samples at a UVA wavelength of 365 nm, and visible wavelengths of 460 nm, 500 nm, and 595 nm. Ambient air-humidity is varied between 20% and 100%. Results show that for high ambient humidity, near 100%, transmission of light through the epidermis is higher than at low ambient humidity, 60% or lower. These results are explained with a simple model of epidermis as a turbid medium and the effect of adsorbed water in reducing light-scattering by refractive-index-matching. Biological implications of increased light-transmission through epidermis at high ambient humidity are discussed.

The effects of dark-broken by UV-B,UV-A,and blue light on fertility of PGMR Nongken 58s

PGMR ( Photoperiod sensitive Genic Male-sterile Rice) Nongken 58s was discovered in1973 by SHI Mingsong, with the characters ofpollen sterile under long daylength(LD) condi-tion but fertile under short daylength (SD)condition during its fertility change stage. LI

光学参量放大器辅助的复合腔磁系统中磁力诱导透明及快慢光效应

提出了一种含有光学参量放大器的复合腔磁系统。利用系统海森堡-郎之万演化方程和输入-输出关系研究了磁力诱导透明和快慢光效应。数值计算表明:当腔磁系统考虑磁振子-声子耦合时,出现双重透明窗口。磁振子-声子之间的耦合强度增强,透明窗口宽度变宽,深度加深。在系统中调控光学参量放大器的增益,吸收光谱在共振频率两侧出现不对称现象,吸收谱曲线的峰值随光学参量放大器增益的增加而变大。通过调节腔磁耦合强度,改变了吸收光谱和色散光谱的传输特性。此外,探测场的传输速率依赖于光学参量放大器的增益。腔磁系统的快慢光效应及其切换通过调控光学参量放大器得以实现。该研究结果可为量子光学操纵和量子信息存储的研究提供参考。

归白祛斑汤结合强脉冲光治疗黄褐斑(肝郁气滞型)临床疗效观察

目的观察黄褐斑(肝郁气滞型)患者采取归白祛斑汤结合强脉冲光治疗的临床效果。方法将纳入的78例肝郁气滞型黄褐斑患者以随机数字表法分为观察组和对照组,每组39例,对照组口服维生素C与维生素E治疗,并给予强脉冲光治疗,而观察组在对照组治疗基础上结合归白祛斑汤治疗。数据观察:临床治疗效果、治疗前后中医证候积分(面部黄褐色斑片、胁胀胸痞、性情急躁易怒、乳房作胀或疼痛)变化、皮损面积与皮损颜色评分变化、皮肤病生活质量指数(dermatology life quality index,DLQI评分)变化、皮肤角质层含水量变化、焦虑自评量表(Self-Rating Anxiety Scale,SAS)评分变化、治疗不良反应。结果对照组与观察组患者治疗总有效率比较[82.05%(32/39)vs97.44%(38/39)],观察组更高,P<0.05;治疗前,两组患者中医证候积分(面部黄褐色斑片、胁胀胸痞、性情急躁易怒及乳房作胀或疼痛)、皮损面积及颜色评分、皮肤角质层含水量与DLQI评分、SAS评分等指标比较,P>0.05,治疗后两组患者中医证候积分(面部黄褐色斑片、胁胀胸痞、性情急躁易怒、乳房作胀或疼痛)、皮损面积与皮损颜色评分、DLQI评分、皮肤角质层含水量、SAS评分均改善,治疗后观察组患者的中医证候积分(面部黄褐色斑片、胁胀胸痞、性情急躁易怒、乳房作胀或疼痛)、皮损面积与皮损颜色评分、DLQI评分、皮肤角质层含水量、SAS评分等指标均优于对照组患者,P<0.05;对照组与观察组患者不良反应均较少,P>0.05。结论归白祛斑汤结合强脉冲光治疗黄褐斑(肝郁气滞型)临床疗效显著,患者症状改善,心理状态改善,生活质量明显提升,且不良反应少,治疗较为安全可靠,值得应用。

Exact Equations for the Light Doppler Effect

The influence of light source on the receiver as electromagnetic interaction is considered. The mechanical influence of the moving charged body on a motionless one is defined in the experimental laws of electrodynamics. These laws determine the changes of parameters of the light source that moves relatively the receiver. The laws of change of light frequency and its direction of the moving source are derived from the laws of electromagnetism. At small velocity of source movement they coincide with classical results: the Doppler effect and phenomenon of aberration. The interaction of the source and receiver depends only on their velocity of movement relatively each other. There is no world medium, the relative movement to which would influence the characteristics of light source.

雷电间接效应多重脉冲组电流产生装置的设计

针对雷电间接效应多重脉冲组电流模拟需求,完成了雷电间接效应多重脉冲组模拟源的设计,采用20个Crowbar电路支路,通过分时放电的方式实现1个脉冲串内多脉冲输出需求,每个支路可以实现最小间隔30 ms的重复频率放电,从而实现3个脉冲串的输出需求。对放电支路的参数进行了详细设计,分析了电容、波尾电路电感、波尾电路电阻参数变化对输出特性的影响。分析了采用并联大电容实现放电电容重复频率快速充电的可行性,完成了装置的初步结构设计并结合装置结构简要分析了电路模拟参数设置的合理性。该装置建成后,可为电子、电气设备等开展测试提供技术支持。

飞机及分系统雷电效应标准及测试浅析

对国内外关军用及民用飞机平台、分系统及设备雷电标准进行分析,针对雷电直接效应和雷电间接效应的所有测试项目,详述每个测试项目的适用区域、波形要求、测试配置等。结合现有国内雷电设计验证标准及测试存在的不足,提出提升测试设备与试验验证技术匹配性、扩展军用标准测试领域、统一同军种同一平台要求等建议。通过对军用机载平台、设备及分系统关于雷电设计验证标准及测试的分析,为相关产品设计师及试验人员提供设计指标参考,明确产品关于雷电防护的设计要求及验证要求,做到有的放矢,提高设计费效比。

数字经济发展与城市收缩——来自夜间灯光数据的证据

数字经济正成为社会经济发展的新动能,它对于抑制城市收缩、促进城市协调发展具有深远影响。利用2011—2021年夜间灯光数据,识别城市收缩,并考察数字经济发展对城市收缩的影响。研究发现,数字经济发展可以显著抑制城市收缩;数字经济发展抑制城市收缩的效应在收缩型城市以及市场化水平低、教育水平低的地区表现得更为明显;城市收入差距、产业结构升级、城市创新创业是数字经济发展抑制城市收缩的重要渠道,加强网络基础设施建设会更有利于数字经济抑制城市严重收缩。进一步研究发现,数字经济发展对城市收缩的影响具有门槛效应,即当数字经济发展达到一定水平后,它对城市收缩的抑制作用才会显现,同时抑制作用具有边际报酬递增的后发性优势。本研究有助于揭示数字经济发展影响城市收缩的作用机制,对于如何利用数字经济有效抑制城市收缩提供了经验支持。

可见光和银离子对p型和n型黄铜矿生物浸出的影响机理

研究可见光和银离子(Ag^(+))对嗜酸氧化亚铁硫杆菌浸出p型和n型黄铜矿(黄铜矿A和黄铜矿B)的不同影响及机理。通过霍尔效应试验、生物浸出试验、X射线衍射、扫描电子显微镜和X射线光电子能谱对黄铜矿的半导体性质、生物浸出行为、表面形貌、主要物相和表面物种进行分析。实验结果表明,黄铜矿A比黄铜矿B具有更高的载流子浓度和更大的载流子迁移率,因此其溶出速率更快。生物浸出24 d后,当光照和Ag^(+)同时存在时,黄铜矿A的铜浸出率为91.05%,比黄铜矿B的铜浸出率(73.19%)高17.86%。显然,可见光和Ag^(+)对黄铜矿A生物溶解过程的促进作用强于黄铜矿B,这主要归因于黄铜矿A具有更高的载流子迁移率。此外,在光照影响下,黄铜矿表面电荷转移加快,导致Ag2S积累增多(特别是黄铜矿A),从而导致钝化层致密结构被破坏,钝化效果降低,黄铜矿溶解加速。

形貌调控及掺杂改性对TiO_(2)催化剂光催化性能的影响

为了改善TiO_(2)光催化活性,通过溶胶-凝胶法制备了介孔TiO_(2)、C/TiO_(2)、Nd/TiO_(2)和C/Nd/TiO_(2),并以聚苯乙烯(PS)胶晶为模板剂制备了多级有序C/Nd/TiO_(2)催化剂。利用SEM、XRD、XPS、UV-Vis DRS和N_(2)吸附-脱附等表征手段对所制备的催化剂性能进行分析。在模拟可见光条件下研究了所制备催化剂材料对甲基橙溶液的光催化性能。结果表明,锐钛矿型多级有序C/Nd/TiO_(2)催化剂表面形貌排列整齐,内部具有交联的孔道结构,大孔形状表现出六边形结构,产生良好的开放性,较大的比表面积和孔容积为传质提供了较大的空间。非金属C和稀土金属Nd通过相互协同作用,使多级有序C/Nd/TiO_(2)的禁带宽度变窄,从而表现出良好的光催化活性,在光照210 min时,其光催化脱色率可达81.15%。

适用于扩展光源且具有阵列编辑性的透镜组设计

利用自由曲面设计并结合斯涅耳定律以及能量守恒定律,设计出一款能实现大面积均匀光斑的透镜组。该透镜组由一块次透镜和一块主透镜组成,其中次透镜对LED发光角进行收缩来减小透镜组结构,而主透镜对能量进行调控来实现均匀度调节。通过蒙特卡洛光线追迹模拟仿真,单个透镜组在接收面呈现方形均匀光斑,有效辐射通量比达到95.5%,均匀度达到95.7%,表明该透镜组具有良好的有效辐射通量比和均匀度;而透镜组阵列在接收面同样呈现方形均匀光斑,有效光通量比和均匀度均大于95%,表明透镜组阵列能够耦合多颗LED面阵列扩展光源,实现更高光功率的均匀光斑,可以用于基于荧光反向测量装置中大功率光源等应用场景。