Faraday Rotation Of Light Research Articles

Massless polarized particle and Faraday rotation of light in the Schwarzschild spacetime

We present the manifestly covariant Lagrangian of a massless polarized particle that implies all dynamic and algebraic equations as the conditions of extreme of this variational problem. The model allows for minimal interaction with a gravitational field, leading to the equations, coinciding with Maxwell equations in the geometrical optics approximation. The model allows also a wide class of nonminimal interactions, which suggests an alternative way to study the electromagnetic radiation beyond the leading order of geometrical optics. As a specific example, we construct a curvature-dependent interaction in Schwarzschild spacetime, predicting the Faraday rotation of polarization plane, linearly dependent on the wave frequency. As a result, the Schwarzschild spacetime generates a kind of angular rainbow of light: waves of different frequencies, initially linearly polarized in one direction, acquire different orientations of their polarization planes when propagated along the same ray.

Nonlinear magneto optic spin Hall effect of transmitted light through a multilayer with graphene in terahertz region

Abstract We first propose the nonlinear spin Hall effect of light (SHEL) and MOSHEL (magneto optic spin Hall effect of light) through a multilayer with graphene and nonlinear substrate (NLS) in terahertz region. The MO transfer matrix method is modified to calculate the SHEL shift in a nonlinear system. The NLS brings bistable characteristics for SHEL in which nonlinear splitting of left-handed circularly polarized (LHCP) and right-handed circularly polarized (RHCP) components can be observed. The Faraday rotation of light in terahertz region causes the asymmetrical SHEL shifts distribution of LHCP and RHCP components. Meanwhile the MO effect of graphene brings modulations for nonlinear SHEL and MOSHEL which provide us new and flexible methods to control spatial light field distribution. In addition, as the delay effect causes the chaos of bistable state system, the SHEL shift can be used as a quantum point for the chaos phenomenon.

Electrical control of Faraday rotation at a liquid-liquid interface.

A theory is developed for the Faraday rotation of light from a monolayer of charged magnetic nanoparticles at an electrified liquid-liquid interface. The polarization fields of neighboring nanoparticles enhance the Faraday rotation. At such interfaces, and for realistic sizes and charges of nanoparticles, their adsorption-desorption can be controlled with a voltage variation<1 V, providing electrovariable Faraday rotation. A calculation based on the Maxwell-Garnett theory predicts that the corresponding redistribution of 40 nm nanoparticles of yttrium iron garnet can switch a cavity with a quality factor larger than 10(4) for light of wavelength 500 nm at normal incidence.

Cosmological Magnetic Field Limits in an Inhomogeneous Universe

We study the effect of inhomogeneities in the matter distribution of the universe on the Faraday rotation of light from distant QSOs and derive new limits on the cosmological magnetic field. The matter distribution in the universe is far from homogeneous, and for the redshifts of interest in relation to rotation measures (RMs), it is well described by the observed Lyα forest. We use a lognormal distribution to model the Lyα forest, and we assume that a cosmological magnetic field is frozen into the plasma and therefore is a function of the density inhomogeneities. The Lyα forest results are much less sensitive to the cosmological magnetic field coherence length than the results for a homogeneous universe, and they show an increase in the magnitude of the expected RM for a given field by over an order of magnitude. The forest also introduces a large scatter in RMs for different lines of sight, with a highly non-Gaussian tail that renders the variance and the mean RM impractical for setting limits. The median |RM| is a better statistical indicator that we use to derive the following limits using the observed RMs for QSOs between z=0 and z=2.5. We set Ωbh2=0.02 and get, for cosmological fields that are coherent across the present horizon, BH−10 10−9 G in the case of a Lyα forest that is stronger than the limit for a homogeneous universe, BhH−10 2×10−8 G; for a 50 Mpc coherence length, the inhomogeneous case gives B50 Mpc 6×10−9 G, while the homogeneous limit is Bh50 Mpc 10−7 G; and for a coherence length equal to the Jeans length, BλJ 10−8 G for the Lyα case, while BhλJ 10−6 G.

Faraday rotation of light in a microcavity

Faraday rotation of light in microcavities is studied theoretically. The reflection and transmission spectra are calculated. It is shown that in the region of the spectrum corresponding to a characteristic mode of the cavity the Faraday rotation is strongly intensified and the polarization of the light changes substantially.