Magnetization-induced second-harmonic generation

Vollmer R 1998 Magnetization-induced second harmonic generation from surfaces and ultrathin films Nonlinear Optics in Metals e6 K H Bennemann (Oxford Clarendon) pp 42-131... 

The amount of change is directly proportional to the magnetization of the reflecting surface layer. The probing depth is about 10-20 nm, thus the method is not particularly surface sensitive [658-660]. If surface specificity is required, magnetization induced second harmonic generation might be useful applications of this method under in situ conditions in electrochemical studies have not been reported so far. 

MSHG Magnetization induced second harmonic generation... 

Wierenga, H., Jong, W. D., Prins, M., Rasing, T., VoUmer, R., Kirilyuk, A., Schwabe, H., and Kirschner, J. (1995). Interface magnetism and possible quantum well oscillations in ultrathin Co/Cu films observed by magnetization induced second harmonic generation. Phys.Rev.Lett., 74 1462 -1465. 

Magnetic nanoparticles showing Faraday rotation effect, and/or Kerr effect can be of interest in the fabrication of switches and devices. Size dependant transmittance and Faraday rotation have been found in maghemite ferrofluids and ferrite films." Multilayered assemblies of yttrium garnet nanoparticles show magnetization-induced second harmonic generation (Kerr effect)." In metal/PMMA nanocomposites, the main absorption band narrows and additional peaks appear when decreasing the particle size." ... 

Koopmans, B., Janner, A.-M., Jonkman, H., Sawatzky, G., and van der Woude, F. (1993). Strong bulk magnetic dipole induced second-harmonic generation from Cgo-Phys. Rev. Lett., 71 3569 - 3572. 

The summation runs over repeated indices, /r, is the i-th component of the induced electric dipole moment and , are components of the applied electro-magnetic field. The coefficients aij, Pijic and Yijki are components of the linear polarizability, the first hyperpolarizability, and the second hyperpolarizability tensor, respectively. The first term on the right hand side of eq. (12) describes the linear response of the incident electric field, whereas the other terms describe the nonhnear response. The ft tensor is responsible for second order nonlinear optical effects such as second harmonic generation (SHG, frequency AotAAin, frequency mixing, optical rectification and the electro-optic effect. The ft tensor vanishes in a centrosymmetric envirorunent, so that most second-order nonlinear optical materials that have been studied so far consists of non-centrosyrmnetric, one-dimensional charge-transfer molecules. At the macroscopic level, observation of the nonlinear optical susceptibility requires that the molecular non-symmetry is preserved over the physical dimensions of the bulk stmcture. 

The first contribution to the polarization induces a modification of the wave propagation in the material, for both its amplitude and phase, but without any frequency change. This phenomenon is known as the optical Kerr effect, by analogy with the magneto-optic and electro-optic Kerr effects where the medium refractive index varies proportionally with the square of the applied magnetic or electric static field. The second contribution corresponds to the third harmonics generation (THG). 

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