双棱镜结构中透射光束的古斯-汉欣位移

当入射角大于全反射临界角时,双棱镜结构中透射和反射光束的古斯-汉欣(Goos-Haenchen)位移具有饱和效应,并且只有波长数量级。利用稳态相位法研究了当入射角小于全反射临界角时双棱镜结构中透射光束的古斯-汉欣位移。研究表明,传播模式下透射光束的古斯-汉欣位移是空气层厚度、入射角和双棱镜折射率的周期性函数。当透射共振时,透射光束的古斯-汉欣位移可达入射波长的几十倍,与入射角大于全反射临界角的情况相比,透射光束的位移通过边界的相互作用具有共振增强效应;在非共振点处,对称结构中的反射光束具有与透射光束相同的古斯-汉欣位移。共振增强的透射光束的位移在光开关及光耦合器中具有潜在的应用。     

物理光学 光学性质、效应

O436 2005053266 双棱镜结构中透射光束的古斯-汉欣位移=Goos-Hanchen shift of the transmitted light beam in a two-prism configu- ration[刊,中]／朱绮彪(上海大学理学院物理系．上海 (200444)),李春芳…∥光学学报．-2005,25(5)．-673- 677 利用稳态相位法研究了当入射角小于全反射临界角 时双棱镜结构中透射光束的古斯-汉欣位移。研究表明, 传播模式下透射光束的古斯-汉欣位移是空气层厚度、入 射角和双棱镜折射率的周期性函数。当透射共振时,透射 光束的古斯-汉欣位移可达入射波长的几十倍,与入射角 大于全反射临界角的情况相比,透射光束的位移通过边界 的相互作用具有共振增强效应;在非共振点处,对称结构 中的反射光束具有与透射光束相同的古斯-汉欣位移。图     

棱镜-薄膜耦合结构中光束Goos-H(a)nchen位移的增强

棱镜-薄膜耦合结构是单侧镀电介质膜的双棱镜结构中的一种,在光信号传输方面具有十分重要的作用.利用稳态相位法分析了这种结构中反射和透射光束的Goos-Hanchen位移,研究结果表明,反射和透射光束的Goos-Hanchen位移随薄膜厚度或入射角的增大除出现共振峰外,还存在反射光束的Goos-Hanchen位移共振峰为负值的新现象.在共振点处透射和反射光束的正向或负向位移量最大可达百余波长.这一结构中薄膜和入射角.对光束Goos-Hanchen位移的调制在设计新型光位移调制和光传感器件中具有潜在的应用.     

格兰-泰勒棱镜空气隙厚度的测量

为了测量格兰一泰勒棱镜空气隙的厚度,分析了棱镜对单模高斯光束的影响.结果表明.经过棱镜后的透射光强随着光束在棱镜端面上的入射角变化呈现周期性的振荡,且振荡特性与入射光的波长,光强分布特性、棱镜结构角及宅气隙的厚度有关.对于给定波长的入射单模高斯光束,由于棱镜的结构角在棱镜胶合之前可以精确测得,所以通过分析这种振荡特性便町以得出棱镜空气隙的厚度.据此设计实验.测出了透射光强随入射角的周期性变化关系.利用计算机编程.間隔改变0.0001 mm作为理论计算中的空气隙厚度的取值.计算实验测得的透射光强振荡周期与理论计算值的相对偏差的平均值,对于样品棱镜,当该值为4.35%时取值最小,此时对应的空气隙厚度为0.0143 mm.     

高斯光束在单轴挛晶界面上的反射与折射

给出了高斯光束入射到挛晶结构的电磁场分布,解出了反射系数和透射系数。根据晶体的色散关系解出了入射角、反射角和折射角关于晶体参量及波矢的方程,并根据角度方程给出了在一定参量下反射角和折射角关于入射角变化的关系图,以图示的方法显示了光束在界面处的异常性质。根据角度关系和反射、透射系数分析了异常光束在界面处能够出现二性折射、负反射、全透射和全反射等光束的奇特性质;分析了出现这些奇特性质对晶体参量和入射角所要求的条件。根据时间平均的能流密度公式,用数值模拟的方法给出了二性折射、全透射和全反射在特定参量下的高斯光束在挛晶内的能流密度分布图及当发生全反射时不同宽度光束在界面处关于入射角的古斯-亨兴(Goos-Hanchen)位移。     

用X射线全反射法测量U基Al膜的厚度与密度分布

利用全反射法分析了U基铝薄膜的反射曲线，以及厚度与密度分布和基体的表面粗糙度情况，讨论了掠射角在临界角或者小于、大于临界角的反射强度情况，并且分析了薄膜的全反射的原理和数据处理方法。     

基于传输矩阵法讨论光疏介质表面的全反射

探究了光在光密介质与超薄光疏介质界面处的全反射,通过在光密介质中嵌入一光疏介质薄层,利用传输矩阵法,定量地分析了入射角度以及光疏介质的厚度对反射率的影响.数值模拟结果表明,当光疏介质的厚度小于约一个波长时,即使入射角大于全反射的临界角,反射率也不一定会达到1,也就是说,光学隧道效应将会出现.     

空气隙偏光镜对单模高斯光束光强分布影响的分析

根据光在格兰泰勒棱镜和格兰傅科棱镜空气隙胶合层中的干涉效应,分析了空气隙偏光棱镜对单模高斯光束光强分布的影响;结果表明:对于某一波长的入射光,当空气隙的厚度一定时,透射光强随光在空气隙介面上入射角的变化作周期性振荡;当入射角一定时,透射光强随空气隙厚度的变化作周期性变化;且透射高斯光束的形状也随光的入射角以及空气隙厚度的改变发生变化;且无论是透射光强的周期性振荡,还是透射高斯光束的形状的变化,格兰泰勒棱镜的影响均小于格兰傅科棱镜;这说明前者的综合性能优于后者。     

马普-赫斯棱镜对单模高斯光束光强分布影响分析

根据光在马普－赫斯棱镜两空气隙胶合层中的干涉效应,分析了其对单模高斯光束光强分布的影响.结果表明,对于某一高斯光束入射棱镜时,透射光束光强将随入射角的变化而呈现周期性的振荡;对于正入射的光束,当空气隙的厚度一定时,透射光强随棱镜两空气隙结构角的变化作周期性振荡;当结构角一定时,透射光强随空气隙厚度的变化作周期性变化;且透射高斯光束的形状也随棱镜结构的改变发生变化,表明,可以通过选择合适的棱镜结构以减小棱镜对透射光束的影响,对于成品棱镜,则可通过改变入射角使棱镜的性能达到较佳状态.     

光波导技术同步测量棱镜及波导薄膜参数

依据全反射理论和棱镜耦合原理,实现了对棱镜折射率及波导薄膜材料折射率和厚度的同步测量。使用高准直半导体激光器激光入射到棱镜内部与波导膜的分界面上,逐步旋转棱镜或改变棱镜的入射角,得到棱镜耦合M线,曲线前面几组的波谷为波导模激发,在M线左侧收尾处有一个不完整波峰,其反射光强随入射角迅速衰减,为全反射时的临界点,由此可实现棱镜及波导薄膜参数的同步测量;用此法测量了棱镜耦合一体化平面波导棱镜的折射率和聚甲基丙烯酸甲酯(PMMA)聚合物波导薄膜的折射率和厚度。测量棱镜折射率精度为±1.9×10-4,波导薄膜折射率和厚度的精度分别为±6.2×10-4 μm和±1.6×10-2 μm。     

Goos-Hänchen shift of the uniaxially anisotropic left-handed material film with an arbitrary angle between the optical axis and the interface

The Goos-Hänchen shift at the surface of a uniaxially anisotropic left-handed material film is investigated, for the situation of that there is an arbitrary angle between the optical axis and the interface of the material. The analytical expressions of the Goos-Hänchen shifts are derived, for both cases of that the total reflection occurs and does not occur at the first interface. The sign of the Goos-Hänchen shifts in the two situations is analysed. The results show that the Goos-Hänchen shift of the reflected wave is the same as that of the transmitted one for the case that the total reflection does not occur at the first interface; the Goos-Hänchen shift of the transmitted wave oscillates as the thickness of the film is increased, and its overall tendency is increased; the Goos-Hänchen shift of the transmitted wave realizes its absolute maximum when the transmitted wave resonances, the absolute maximum is almost several 10 times of the wavelength of the incident wave; the Goos-Hänchen shift of the transmitted wave is significantly influenced by the incident angle and the angle between the optical axis and the interface.     

Method of measuring one-dimensional photonic crystal period-structure-film thickness based on Bloch surface wave enhanced Goos-Hänchen shift

This paper puts forward a novel method of measuring the thin period-structure-film thickness based on the Bloch surface wave (BSW) enhanced Goos-Hänchen (GH) shift in one-dimensional photonic crystal (1DPC). The BSW phenomenon appearing in 1DPC enhances the GH shift generated in the attenuated total internal reflection structure. The GH shift is closely related to the thickness of the film which is composed of layer-structure of 1DPC. The GH shifts under multiple different incident light conditions will be obtained by varying the wavelength and angle of the measured light, and the thickness distribution of the entire structure of 1DPC is calculated by the particle swarm optimization (PSO) algorithm. The relationship between the structure of a 1DPC film composed of TiO₂ and SiO₂ layers and the GH shift, is investigated. Under the specific photonic crystal structure and incident conditions, a giant GH shift, 5.1×10³ times the wavelength of incidence, can be obtained theoretically. Simulation and calculation results show that the thickness of termination layer and periodic structure bilayer of 1DPC film with 0.1-nm resolution can be obtained by measuring the GH shifts. The exact structure of a 1DPC film is innovatively measured by the BSW-enhanced GH shift.     

Spin Hall effect of light in one-dimensional photonic crystal

We established a general propagating model to investigate the spin Hall effect of light in one-dimensional photonic crystal. A polarized (spin dependent) Gaussian beam which was incident obliquely through one-dimensional photonic crystal was demonstrated. Having decomposed a polarized Gaussian beam into different plane wave components charactering individual wave vectors, we revealed the transmission coefficient and reflection coefficient of each plane wave which propagates through the one-dimensional photonic crystal. It enabled us to obtain exact solution to the electric field of transmitted and reflected beams, and the analytical formula of light intensity, accordingly. A method based upon the partial differentials with the intensity distribution of the transmitted and reflected Gaussian beams was presented to determine the transverse and longitude shifts explicitly. Spin dependent shifts in one-dimensional photonic crystal provide alternative evidence for the spin Hall effect of light.     

Positively and negatively large Goos–Hänchen lateral displacements from a symmetric gyrotropic slab

A detailed study on the lateral displacements of a transverse magnetic (TM) wave transmitted and reflected from a symmetric gyrotropic slab is presented. We give the analytic formulas for the transmission coefficient and the reflection coefficient, as well as the corresponding lateral displacements. It is found that due to the external magnetic field the displacement of a transmitted beam is different from that of reflected one, even for a lossless symmetric configuration. Furthermore, within the chosen frequency band, when the incident angle is near the Brewster angle, the shift of a reflected wave can be large with nonzero reflectance, and can be positive or negative depending on the direction of the applied magnetic field and the incident wave.     

Reflection and transmission of an Airy beam in a dielectric slab

The reflection and transmission of a finite-power Airy beam incident on a dielectric slab are investigated by an analytical method. Based on the plane-wave angular spectrum expansion and Fresnel approximation, the analytical expressions of the reflected field, internal field as well as transmitted field in each region are obtained. Through numerical simulations, the intensity distributions of the incident beam, reflected beam, internal beam as well as transmitted beam are presented at oblique incidence. Besides, we also compare the intensity distributions of the geometrical-optics beam field, the first order beam mode field and the actual beam field, which indicates that the contribution of each order beam mode field to the actual beam field is related to the refractive index of the dielectric slab. Meanwhile, the reflection characteristics of the Airy beams in the special cases of Brewster incidence and total reflection are investigated. Finally, the effects of the optical thickness and refractive index of the dielectric slab on the peak intensity distributions and beam shifts of the reflected and transmitted beams are also discussed in detail. The analytical and numerical results will be useful to analyze the propagation dynamics of Airy beam in the dielectric slab and provide some theoretical supports to the design of optical film.     

Frustrated Total Internal Reflection: Resonant and Negative Goos–Hänchen Shifts in Microwave Regime

It is well-known that the variations of Goos–Hänchen shifts (GHSs) are closely associated with the energy flux provided by evanescent states in the case of total internal reflection. However, when the frustrated total internal reflection (FTIR) is realized with double-prism system operated in the microwave frequency, we observe that the GHSs for the reflected beam show periodic, resembling the phenomenon for transmitted beams reported in the literatures, versus either the operating frequency or the air layer thickness, which is different from the variation of the corresponding reflected energy. Moreover, in another FTIR based system fabricated by a composite absorptive material slab with a two-dimensional top layer of frequency selective surface (FSS), the GHSs for reflected beam are discovered as not only resonant but also negative with the incidence of transverse electric that is TE polarized, just as predicted theoretically in the literatures.     

Phase control of Goos-Hänchen shifts in a four-level quantum dot nanostructure

In this letter, phase control of the Goos-Hänchen shifts of the reflected and transmitted probe light beams through a cavity containing four-level InGaN/GaN quantum dot nanostructure is theoretically discussed. In order to achieve the wave functions and their corresponding energy levels of the mentioned quantum dot nanostructure, Schrödinger and Poisson equations must be solved in a self consistent manner for carriers (here electron) in quantum dot. It is found that the coupling field, the pumping field as well as the cycling field can enhance the GH shifts of the reflected and transmitted probe beams. The effect of relative phase and the detuning of the probe light on the GH shifts of the reflected and transmitted probe beams are also investigated. We find that the GH shifts can be switched between the large positive and negative values by adjusting the controllable parameters.     

Controllable Goos-Hänchen shift in graphene triangular double barrier

We study the Goos-Hänchen (GH) shifts for Dirac fermions in graphene scattered by a triangular double barrier potential. The massless Dirac-like equation was used to describe the scattered fermions by such potential configuration. Our results show that the GH shifts is affected by the geometrical structure of the double barrier. In particular the GH shifts change sign at the transmission zero energies and exhibit enhanced peaks at each bound state associated with the double barrier when the incident angle is less than the critical angle associated with total reflection.