The interrelation between the Faraday effect and the inverse Faraday effect in a magnetic medium and the terahertz inverse Faraday effect in single molecule magnets

The interrelation between the Faraday and the inverse Faraday effects when the magneto-dipole interaction of a sample with an electromagnetic wave is essential has been phenomenologically investigated. This investigation was carried out in the spirit of well-known Pitaevsky’s approach. The terahertz inverse Faraday effect in single molecule magnets has been theoretically studied, the conditions favorable for observing this effect have been formulated.     

Observation of Ramsey fringes in nonlinear Faraday rotation

The evolution of Δm = 2 ground state coherences was investigated in a thermal Rb atomic beam using spatially separated laser beams. The coherence was created by optical pumping with a linearly polarized light beam and was probed, after evolving in a homogeneous magnetic field via the rotation of the plane of polarization of a second light beam. The observed signal shows dispersively shaped Ramsey fringes with a fringe width of 6 kHz.     

Faraday effect in glass fibers

Various types of glass fiber were studied to determine their suitability for transmitting linearly polarized light. Polarization and magnetooptical experiments were performed on index-gradient fibers. These fibers have birefringent properties as a result of mechanical stress created during fabrication. The interaction of double refraction and the Faraday effect in a longitudinal magnetic field is explained theoretically. The rule governing such fibers in industrial magnetic fields is that the Faraday rotation (φ < 5°/cm) per field length is always substantially smaller than the phase difference (δ_s = 57.2°/cm) per fiber length.     

法拉第旋转的演示实验

介绍一种法拉第旋转的演示实验，实验中使用一种自制的放射状检偏器，利用它可以直观地显示地拉第旋转角随磁场变化的现象。     

Influence of transverse magnetic fields and depletion of working levels on the nonlinear resonance Faraday effect

The nonlinear resonance Faraday effect is studied under the condition of coherent population trapping in ⁸⁷Rb vapor at the D₁-line F=2→F′=1 transition. The influence of transverse magnetic fields on the nonlinear optical Faraday rotation is studied. For the transverse fields perpendicular to the electromagnetic-wave polarization, a simple theoretical model is proposed, which is in good agreement with experimental data. The optimal intensity providing the maximum sensitivity is found based on the results obtained. The influence of working-level depletion on the parameters of Faraday rotation in open systems is studied experimentally and theoretically. The system was closed in the experiment by using an additional laser to increase the sensitivity and extend the dynamic range of measured fields. The importance of compensating for the depletion in the presence of spurious magnetic fields is shown; in particular, the sensitivity was enhanced by a factor of 50 in experiments with a buffer gas.     

Faraday effect in nanogranular Co-Sm-O films

The Faraday effect (FE) was studied in Co-Sm-O composite films consisting of nanoparticles of metallic cobalt embedded in a samarium oxide dielectric matrix. The volume of the magnetic phase was ～60%. The FE spectral dependence for the condensates studied revealed a substantial change as compared to that for bulk cobalt samples, as well as for the films of nanocrystalline Co and CoSm films prepared in this study. An enhancement of the FE was also observed in the short-wavelength part of the optical spectrum.     

Anisotropy of the Faraday effect in crystalline quartz

The anisotropy of the Faraday effect in crystalline quartz was measured for the first time. The optical-wedge method was used to investigate the Faraday effect under conditions of strong linear birefringence and optical activity. Fiz. Tverd. Tela (St. Petersburg) 40, 2035–2036 (November 1998)     

Acoustic Faraday effect in superfluid He-B

We have observed that the direction of linearly polarized transverse sound in superfluid ³He-B rotates in a magnetic field. This acoustic Faraday effect proves the existence of a propagating transverse sound mode in ³He and provides clear evidence for spontaneously broken relative spin–orbit symmetry.     

Theory of the inverse Faraday effect in metals

An analytic expression is given for the inverse Faraday effect, i.e., for the magnetization occuring in a transparent medium exposed to a circularly polarized high-frequency electromagnetic wave. Using a microscopic approach based on the Drude approximation of a free-electron gas, the magnetization of the medium due to the inverse Faraday effect is identified as the result of microscopic solenoidal currents generated by the electromagnetic wave. In contrast to the better known phenomenological derivation, this microscopic treatment provides important information on the frequency dependence of the inverse Faraday effect.     

Multiple reflections in the theory of the Faraday effect

In the case of the transmission of linearly polarized light, of angular frequency ω, through a single medium, surrounded by vacuum on both sides, Donovan and Medcalf have given an exact treatment of multiple reflections in the theory of the Faraday effect. For the purpose of treating transmission through more complicated systems, Piller showed that, for ω_c < ω (where ω_c is the cyclotron frequency), the problem is amenable to a simpler analysis. In the case of thin samples, we have been able to obtain simple analytic results expressing the multiple reflection rotation as a simple multiple of the single-pass result. In particular, we show that the two models are in disagreement for the case of weak absorption in thin samples. We also present a generalization of the Donovan-Medcalf results to the case of three distinct media.     

Polariton enhancement of the Faraday magnetooptic effect

Enhancement of the Faraday magnetooptic effect by the excitation of surface polariton on an interface between an iron garnet and silver is observed. The main contribution to this effect is due to the rotation of the polarization of a surface polariton as the polariton propagates along the interface. Pis’ma Zh. éksp. Teor. Fiz. 68, No. 5, 376–379 (10 September 1998)     

金属中逆法拉第效应的经典理论

研究电子在圆偏振光驱动下的经典动力学问题以及金属中逆法拉第效应(IFE)的经典微观机制.得到电子在圆偏振光驱动下的一个解,表明其运动轨道是螺旋线.忽略电子与磁场的相互作用,电子作绕平行于其初速度的轴、横截面为椭圆的螺旋线运动,产生了一个平行于其初速度、方向由圆偏振光的手征性决定的磁矩.磁矩的统计结果与Hertel从电子气整体出发得到的结果一致.     

The Faraday effect in two-dimensional magneto-photonic crystals

The necessary conditions for the observation of the Faraday effect in 2D magneto-photonic crystals are discussed. It is found. that the Faraday effect may be observed in the directions where any couple of the wave vectors of the harmonics consisting the Bloch waves of TE and TM solutions in zero magnetic field are identical. This direction corresponds neither to Faraday nor to Voigt geometry.     

Spectroscopic observation of the Faraday effect in the far infrared

The Faraday effect was observed in the far-infrared spectrum of NO(2) for what is believed to be the first time. A systematic investigation of the magneto-optical signal as a function of the uncrossing angle between the polarizers was performed. Differences from similar experiments performed in the infrared and the visible regions were encountered. Moreover, a fit of the experimental data allowed calculation of the difference in the real and the imaginary terms of the refractive index for DM(F)=+1 and DM(F)=-1 multiplets.     

Topological shifts in the Aharonov-Bohm effect

The topological nature of the Aharonov-Bohm effect is examined. The interference terms are found to contain the usual flux dependent shift as the dominant observable effect and an additional topological shift unnoticeable in the two-slit interference experiment.