The zero‐dimensional polymer [Pb6(μ2OOCCH=CHFc)2(μ3‐OOCCH=CHFc)2(μ2‐η2‐OOCCH=CHFc)2(η2‐OOCCH=CHFc)2(μ4‐O)2] (1), the one‐dimensional chain polymers [Pb(η1‐μ2‐OOCCH=CHFc)2(phen)]n (phen = phenanthroline; (2), {[Cd(μ2‐η2‐OOCCH=CHFc)(η2‐OOCCH=CHFc)(H2O)2](H2O)4}n (3), and the two‐dimensional hybrid polymer {[Cd(η2‐OOCCH=CHFc)(bbbm)1.5Cl]·1.5H2O}n [bbbm = 1,1'‐(1,4‐butanediyl)bis‐1H‐benzimidazole; 4] have been prepared by the reaction of sodium β‐ferrocenylacrylate [FcCH=CHCOONa, Fc = (η5‐C5H5)Fe(η5‐C5H4)] with the appropriate metal salts. Solution‐state differential pulse voltammetry for 1–4 indicated that the half‐wave potentials of the ferrocenyl moieties in these polymers are all shifted to positive potential compared with that of sodium β‐ferrocenylacrylate. The four polymers’ third‐order nonlinear optical (NLO) properties were determined by the Z‐scan technique in DMF solutions. The results show that these polymers possess good nonlinear optical refraction effects. Their hyperpolarizability (γ) values are calculated to be 4.80 × 10–30, 5.19 × 10–30, 1.57 × 10–29, and 2.04 × 10–29 esu for 1–4, respectively. The γ values of the CdII polymers (3 and 4) are slightly larger than those of the PbII polymers (1 and 2), which indicates that the metal ions play an important role in the NLO properties of these polymers. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

We demonstrate an all-optical strategy for realizing spherical three-dimensional (3D) super-resolution (∼λ3/22) spot arrays of pure longitudinal magnetization by exploiting a 4π optical microscopic setup with two high numerical aperture (NA) objective lenses, which focus and interfere two modulated vectorial beams. Multiple phase filters (MPFs) are designed via an analytical approach derived from the vectorial Debye diffraction theory to modulate the two circularly polarized beams. The system is tailored to constructively interfere the longitudinal magnetization components, while simultaneously destructively interfering the azimuthal ones. As a result, the magnetization field is not only purely longitudinal but also super-resolved in all three dimensions. Furthermore, the MPFs can be designed analytically to control the number and locations of the super-resolved magnetization spots to produce both uniform and nonuniform arrays in a 3D volume. Thus, an all-optical control of all the properties of light-induced magnetization spot arrays has been demonstrated for the first time. These results open up broad applications in magnetic-optical devices such as confocal and multifocal magnetic resonance microscopy, 3D ultrahigh-density magneto-optic memory, and light-induced magneto-lithography.

Nonlinear refraction and absorption in carbon disulfide (CS2) has been investigated using the Z-scan technique with a femtosecond pulse laser at a wavelength of 800 nm in a broad intensity range. It is found that the origin of nonlinearity depends on the laser intensity. At low intensity, the nonlinearity is mainly due to the third-order process. The third- and fifth-order processes are at present simultaneously at high intensity. We also find the critical intensity value which determines whether the fifth-order nonlinear process exists or not by analysis of the divided Z-scan curves at different intensities. The nonlinear absorption is attributed to the three-photon absorption and the nonlinear absorption coefficient is 1.37 × 10−27 m3 W−2.

No abstract