Surface anisotropy in optical second harmonic generation. I. Al(111)

Magnetization-induced second-harmonic generation of light by exchange-coupled magnetic layers

“…3). Furthermore, as was pointed out by Petukhov and Liebsch, 27 and if one extends the results of ab initio calculations obtained for Al(111) to our case, z (2) must originate from a much thinner interface region (ϳ0.1 nm) than the two other components, x (2) and y (2) (ϳ1 nm). This result supports the highly selective nature of the transverse pp MSHG to the upper SiO 2 /Fe 96 Si 4 interface, where there is a large contrast between diagonal permittivities.…”

“…Thus, if one assumes that yxx is similar for the two interfaces, the two contributions must be efficient. This result is even better supported 27 by the fact that y (2) probes a thicker region than z (2) . As in transverse sp MSHG, the longitudinal ps MSHG hysteresis loop exhibits a rather large coercivity, which means again that the second Fe 96 Si 4 interface contributes more.…”

“…This effect has been discussed for particular situations. 26,27 (iii) Radiating point dipoles v (2) on the vth interface imply modified boundary conditions of the electric and magnetic fields at interfaces. 24,28 The relationship between v (2) and outgoing electric field amplitudes ⑀ ⌸,v (2) at 2 frequency (with ⌸ ϭ ͕s, p͖ polarization states) is written as …”

Energy Conservation and the Manley-Rowe Relations in Surface Nonlinear-Optical Spectroscopy

“…An enormous progress has been achieved in experimental applications of the surface nonlinear-optical spectroscopy to study different systems [4]. On the other hand, although a number of theoretical studies of surface SHG [5][6][7][8] and a few extensions of the theory to surface SFG spectroscopy [9][10][11] have been reported, there are still various unsolved problems in understanding the fundamental physics of the surface nonlinear interactions. For threewave interactions in centrosymmetric bulk media the energy relations were first considered by Pershan [12], who constructed the free energy for transparent centrosymmetric systems with quadrupole-allowed nonlinearity.…”

Interdiffusion and magnetism of the Co/Rh interface studied by magnetization induced second harmonic generation

“…This apparent difference does not mean that there are two activation barriers, but must be a result of the fact that P and S polarizations can have different probing depths. 9 Though MSHG is intrinsically interface sensitive due to the symmetry breaking, the nonlinear optical response for S-polarized input can be affected by a deeper layer (ϳ10-50 Å͒ than that for P-polarized light. Assuming the bulk contribution to be unaffected ͑or much less affected͒ by anything that happens at the interface, then this effectively reduces the interface sensitivity of MSHG for this polarization.…”