We report on the growth of GdCa4O(BO3)3 (GdCOB) and YCa4O(BO3)3 (YCOB) crystals and their characterization as new nonlinear optical materials. The crystals with good optical quality were grown by the Czochralski method. YCOB, the characteristics of which has not previously been reported to our knowledge, has a larger temperature acceptance bandwidth than that of GdCOB, and third harmonic generation of a Nd:YAG laser in this crystal was demonstrated.

Continuous-wave power of 189 mW at 473 nm with 49% conversion efficiency is generated from a 8.5 mm long uncoated periodically polled MgO:LiNbO3 ridge-type waveguide by frequency doubling of a diode end-pumped Nd:Y3Al5O12 laser at room temperature; the corresponding internal blue power and conversion efficiency were 222 mW and 58%, respectively. The highest conversion efficiency of 63% (74% with respect to the blue internal power) was obtained from a 12 mm long waveguide with 99 mW blue output power. Saturation of output blue power was observed for coupled fundamental power into the waveguides in excess of 200 mW.

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Perturbations propagating perpendicularly to a zero-order gradient direction are studied in an inhomogeneous |3 > 1 plasma. (Zero-order temperature, density and magnetic-field gradients are assumed to be parallel.) Coupling between hydrodynamic motion, thermal waves and magnetic-field evolution yields four modes of oscillation. The case of zero initial magnetic field extends previous results by inclusion of hydrodynamical effects. In the case of a magnetically insulated wall-confined plasma (cJ e T e > 1,0 > 1), some of the modes can be driven unstable. An upper limit on gradients is given for such wall-confined plasmas to be stable. The connection with anomalous |3 ^ 1 transport is briefly discussed.

In order to study the valence state in the mixed-valence binuclear ferrocenes, X-ray absorption spectra near the Fe K-edge were measured using synchrotron radiation. Well-resolved lines in the spectra obtained for ferrocene derivatives were assigned to the 1s→3d, 1s→Cp(π*), and 1s→4p transitions, respectively, based on the molecular orbitals. There is an apparent difference in the 1s→3d transitions between trapped-valence compounds and averaged-valence compounds in the I3− salts of the monocation of binuclear ferrocenes. The valence states of the mixed-valence binuclear ferrocenes were also studied by X-ray photoelectron spectroscopy.