稀磁半导体Cd_（1－x）Fe_xTe的磁光光谱

在７０－３００Ｋ温度范围内测量了组分ｘ为０．０１和０．０４的Ｃｄ１－ｘＦｅｘＴｅ及ＣｄＴｅ的法拉第效应随入射光子能量的变化，首次获得了Ｃｄ１－ｘＦｅｘＴｅ在布里渊区Γ点和Ｌ点的有效ｇ因子及其与温度的关系。给出了Ｆｅ２＋离子与载流子间的ｓｐ－ｄ交换作用常数Ｎ０（β－α）＝（－１．５７±０．０３）ｅＶ。     

磁光克尔和法拉第效应的完整测量

简单叙述了克尔效应和法拉第效应的原理，并从光谱学研究的角度，对克尔和法拉第旋转角和椭偏率完整磁光参数的若干种实验测量作了介绍和讨论；讨论了一种可供实用的傅里叶磁光谱分析法，可以用较少的并且是无色散的光学元件，通过旋转检偏器，对出射光强随检偏角变化的关系，作傅里叶变换，就可直接可见光区求得完整的克尔和法拉第磁光参数，同时还给出了具体的实例和测量研究的结果。     

Ⅱ—Ⅵ族稀磁半导体ZnSe／Zn1—xMnxSe超晶格中的应力效应

本文通过Ⅱ－Ⅵ族稀磁半导体超晶格ＺｎＳｅ／Ｚｎ１－ｘＭｎｘＳｅ的光致发光谱的测量，对其应力效应进行了讨论。样品的组分ｘ＝０．２，０．３，０．４，测量温度为Ｔ＝１１￣３００Ｋ。结果表明：由于应力效应，ＺｎＳｅ／Ｚｎ１－ｘＭｎｘＳｅ超晶格中的激子能量随ｘ值增加而发生红移。在相同组分下，不同阱、垒宽度比使应力的分布产生明显变化，从而影响超晶格中激子能量。实验与理论计算结果相一致。超晶格中光致发光峰随温度     

碳对α的非卢瑟福背散射截面研究

报道了散射角为１７０°±１．５°，α粒子能量在５－９．０ＭｅＶ之间，ｃ的背散射截面的实验测量值；用Ｒ矩阵理论，通过与实验数据拟合，分析、给出了一套能级参数，并计算了能量范围在２－９．０ＭｅＶ，ｃ的背散射截面；讨论了对背散射分析感兴趣的窄而孤立的强共振峰４２５０±１０ＫｅＶ随靶厚、角度的变化关系以及截面变化缓慢的平坦区３．６－４．２０ＭｅＶ，６．４２５－６．７００ＭｅＶ能区的截面值与背散射角度的关系。 关键词：     

磁光克尔效应中的光子自旋分裂

光子自旋霍尔效应类似于电子系统中的电子自旋霍尔效应, 是在折射率梯度和光子分别扮演的外场和自旋电子的角色下, 由自旋-轨道相互作用而产生的光子自旋分裂现象. 光子自旋霍尔效应为操控光子提供了新的途径, 同时也提供了一种精确测量相关物理效应的方法. 本文研究了磁光克尔效应中光子自旋分裂现象, 建立了磁光克尔旋转与光子自旋霍尔效应之间的定量关系, 并通过弱测量系统观测了磁场作用下铁膜表面的光子自旋分裂位移, 得到相应的磁光旋转角, 验证了我们所推导的理论预测. 本文的研究成果为精确测量磁光克尔系数和磁光克尔旋转角提供了一种新方法.     

“快”带电离子通过固体时的“尾流”效应

简略介绍了“尾流”效应（ｗａｋｅｅｆｆｅｃｔ）的等离子体模型，并依之模拟计算了１．９１５ＭｅＶＨ、２．０６０ＭｅＶＨ在１００Ａ碳膜中分解后０°方向的能谱形式。给出了相同条件下的实验结果，将两者做了比较。     

NH3的同步辐射光电离

用同步辐射光在１０．０－１１．８ｅＶ能量范围内测量了ＮＨ３的光电离效率曲线，观察到在台阶状的离子振动谱上叠加了丰富的自电离结构。通过相应振动结构分析，得到ＮＨ３分子离子基电子态的振动波数ωｅ和非谐性常数（ωｅχｅ），对于出现的自电离结构可归类于ｎｓａ１（ｎ＝５，６），ｎｐａ１（ｎ＝５，６）和ｎｐｅ（ｎ＝６，７）Ｒｙｄｂｅｒｇ系列。     

电子电离钠原子的Cooper最小效应

给出电子电离原子的Ｃｏｏｐｅｒ最小效应的测量方法,测得电子能量为４１．６ｅＶ时钠原子存在一个Ｃｏｏｐｅｒ最小值。     

S波段1＋腔热阴极微波电子枪研究

叙述了１＋腔热阴极微波电子枪设计、制造与调试的情况。该枪已于１９９２年１２月调试出束，经过一年多的调试运行，测量了电子束的发射度和能谱，得到了满意的结果。当输入功率约１．１ＭＷ时，输出电子束最大能量１ＭｅＶ，平均电子能量０．６ＭｅＶ，宏脉冲电流１Ａ，宏脉冲宽度约２μａ，重复频率５０Ｈｚ，微波工作频率２９９７．７５ＭＨｚ，束流归一化发射度ε_ｎ≈５πｍｍ·ｍｒａｄ。     

Si／Ge应变层超晶格的椭偏光谱

测量了几种不同组分的（Ｓｉ）Ｍ／（Ｇｅ）Ｎ应变超晶格材料的椭偏光谱（２．０～５．０ｅＶ），并得到了其介电函数谱；应用介电函数的临界点理论，研究了（Ｓｉ）Ｍ／（Ｇｅ）Ｎ应变超晶格材料的光学性质。发现短周期Ｓｉ／Ｇｅ应变超晶格除了具有明显的Ｅ１和Ｅ２带间跃迁外，还存在与应力和超晶格能带的折迭效应有关的跃迁峰，其能量分别位于２．３～３．０ｅＶ和３．３～４．０ｅＶ范围内     

Interference effects in transient Kerr spectra of a semiconductor multilayer structure

We experimentally study the spectra of the transient Faraday and Kerr effects near exciton resonances of a GaAs multiple quantum well. A multilayer calculation with a transfer matrix model accounts quantitatively for the linear transmission (reflectivity) spectra and the Faraday (Kerr) spectra. The Faraday and Kerr spectra do not obey a Kramers-Kronig relation. This phenomenon was found to be due to the multiple reflection effects on the Kerr spectra.     

铁磁薄膜中圆偏振光感应的瞬态磁光Kerr峰的物理起源

使用飞秒时间分辨抽运-探测磁光Kerr光谱技术,实验研究了圆偏振光抽运面内磁化FePt和垂直磁化GdFeCo薄膜的磁化演化动力学,发现在时间延迟零点处均出现瞬态Kerr峰.分析了此Kerr峰的起源,指出此瞬态Kerr峰与铁磁性无关,可能起源于自由电子的顺磁磁化,而顺磁磁化的外磁场来自圆偏振抽运光的逆Faraday效应.基于顺磁磁化模型的计算结果支持此观点.基于此观点,逆Faraday效应感应的磁场脉冲宽度应该与激光脉冲宽度一致.     

Optical and magneto-optical properties of nanostructured yttrium iron garnet

Bulk dense samples of nanostructured yttrium iron garnet Y₃Fe₅O₁₂ with crystallite sizes of 20–40 nm are prepared by high-pressure torsion from a garnet powder with micron grains. The absorption and Faraday rotation spectra in the IR range and the transverse Kerr effect spectra in the visible spectral range for these samples are measured. The absorption and magneto-optical effect spectra are in agreement with the corresponding spectra of single crystals. The appearance of additional absorption bands at 2 and 3 μm is associated with the violation of the stoichiometry of the nanogarnet and the possible contamination of the initial material. The specific Faraday rotation in the transparency window is approximately 1.5 times smaller than the corresponding quantity for single crystals. The extrema in the Kerr effect spectra coincide with those for single crystals, are smaller in magnitude, and are smeared. On the whole, the prepared bulk samples are transparent in the IR spectral range and exhibit optical and magneto-optical characteristics comparable to the corresponding parameters for single crystals. The high density of point defects of the nanogarnet is primarily due to the violation of the stoichiometry and the valence state of iron ions.     

Magneto-optical polarization spectroscopy with soft X-rays

X-ray magneto-optical polarization spectroscopy is a relatively new ellipsometric technique with which the complete polarization state of X-ray radiation after its interaction with magnetic matter can be measured. This comprises rotation and ellipticity, which fully quantify the lights polarization. Employing this technique, the complete magneto-optical constants in the X-ray regime can directly be obtained, in contrast to the more commonly used intensity-only measurements. The Faraday and magneto-optical Kerr effects, being odd with respect to magnetization reversal, can be used for the examination of ferromagnetic (FM) materials. This we demonstrate here with Faraday and Kerr rotation and ellipticity spectra, measured at the 2p edges of Fe, Co, and Ni. The Voigt effect and magnetic linear dichroism (XMLD), which are even with respect to magnetization reversal, are applied to probe both FM and antiferromagnetic (AFM) materials. Using a new XMLD-reflection spectroscopy we present results obtained on technologically important buried AFM NiO layers. PACS 78.20.Ls; 78.70.Dm; 75.70.-i     

非线性克尔效应对飞秒激光偏振的超快调制

研究了近红外飞秒激光的偏振在太赫兹频率的超快调制.利用抽运-探测光谱技术,通过改变两个脉冲之间的延迟时间可以控制光脉冲的旋转角.在Li：NaTb（WO₄）₂磁光晶体中观察到探测光的偏振随延迟时间变化的高速振荡,振荡信号的中心频率为0.19 THz.这种超快偏振调制现象可以解释为,抽运-探测实验构置中,前向传播的抽运光诱导的光学克尔非线性引起被晶体远端表面所反射的背向传播的探测光脉冲偏振面的额外旋转.通过改变抽运光的圆偏振旋性可以控制探测光调制信号的相位和振幅.实验结果表明,非线性光学克尔效应可以作为一种全新的手段,在磁光晶体中实现近红外飞秒激光以太赫兹频率的超快偏振调控.这将在超快磁光调制器等全光器件中得以应用.实验结果将有助于偏振依赖的超快动力学过程的研究.     

Extraordinary magneto-optical effects and transmission through metal-dielectric plasmonic systems

We predict theoretically a significant enhancement of the magneto-optical Faraday and Kerr effects in the bilayer systems of a metallic film perforated with subwavelength hole arrays and a uniform dielectric film magnetized perpendicular to its plane. Calculations, based on a rigorous coupled-wave analysis of Maxwell's equations, demonstrate that in such structures the Faraday effect spectrum has several resonance peaks in the near-infrared range, some of them coinciding with transmittance peaks, providing simultaneous large Faraday rotation enhanced by an order of magnitude and high transmittance of about 35%.     

The subwavelength tuned magneto-optical Kerr effect in L1_0-FePt films with perpendicular magnetic anisotropy

For L10-FePt films with strong perpendicular anisotropy covered by arrays of hexagonal close-packed polystyrene spheres(PSSs),fine structures are observed in magneto-optical Kerr rotation spectra in the visible spectral range.The reflection minima are found to be located at the same wavelengths as the Kerr rotation peaks.The Kerr rotation enhancement is attributed to the excitation of both the surface plasmon polariton in the dielectric PSS/metal interface and the guide waves(guide mode)in the PSS array.The two-dimensional PSSs/SiO2/FePt system exhibiting a tunable magneto-optical Kerr effect and a high perpendicular magnetic anisotropy will be helpful for designing and fabricating magneto-optics devices.     

A novel method for simultaneous measurement of current and voltage using one low-birefringence fiber

A novel method for simultaneous measurement of current and voltage employing a single monomode low-birefringence (Lo-Bi) fiber is described. This uses the Faraday effect for detection of current and the Kerr effect for detection of voltage. The waveform of the output light intensity due to the Kerr effect has been detected and the Kerr constant was measured as 5.4×10⁻¹⁶ m/V⁻² at 25°C. Theoretical analysis shows that the current component can be measured free from the influence of the voltage component and the two components can be easily separated.     

磁流体制备及性质研究

采用化学共沉淀法制备了纳米Fe3O4磁性颗粒,将其均匀分散在载液中获得磁流体.给出了表征所制备样品的宏观和微观特性图谱,探究了样品的磁热效应、法拉第效应和克尔效应,并制作了磁流体薄膜显示器.通过对磁流体样品的分析,获得其最佳的油酸钠包裹量为0.0216g/mL,样品颗粒小,稳定性高,磁热效应明显.研究发现磁流体薄膜的透射率随磁场变化明显,测量费尔德系数时必须考虑透射率的影响.磁流体样品存在异常克尔信号.     

Spectral dependence of Faraday rotation in magnetite-polymer nanocomposites

We report the size-dependent magneto-optical properties of nanometer-sized magnetite particles embedded in poly(methyl methacrylate). The nanocomposite material contains Fe₃O₄ particles with diameters ranging from 8 to 200 nm. Faraday rotation spectra are measured in the wavelength range of 400-900 nm. A broad spectral band centered at 650 nm (1.91 eV) is observed in the for the larger (200 nm) particles. Decreasing of nanoparticle size leads to a significant narrowing of this band and appearance of an additional peak in the 2.5-3.2 eV range. We propose that the changes to the spectrum are caused by structural changes in the small particles, which affect the magneto-optically active charge transfer and orbital promotion electronic transitions. In addition, the Faraday rotation spectrum of the composite containing 8 nm particles is sensitive to nanoparticle concentration. Increasing the concentration of nanoparticles in the composite results in a red shift of the spectral feature at approximately 450 nm. We propose that the shift of the peak in Faraday rotation spectrum is due to particle-particle interactions in the concentrated sample. Ferromagnetic Resonance measurements confirm a magneto-static interaction in the concentrated sample not present in the diluted sample.