No abstract

The electronic and structural properties of LiB 3 O 5 (LBO) surfaces have been studied by X-ray photoemission spectroscopy (XPS) and reflectance high-energy electron diffraction (RHEED). The as-grown (110) crystal face and mechanically polished (001) surfaces have been investigated comparatively. Electronic structure of LBO has been determined on as-grown (110) crystal face previously cleaned by chemical etching with RHEED control. The correlation of valence band structure and measured binding energies with earlier reported results has been discussed. Core-level spectroscopy reveals strong enriching of mechanically polished LBO surface with carbon, when nanodiamond powder is used as an abrasive. So high carbon level as C:B=0.7 has been observed at the surface while the ratio Li:B:O remains according to LBO chemical composition. The association of LBO Kikuchi-lines with strong background has been shown by RHEED analysis of the surface. Thus, the polished LBO surface constitutes a high structure quality LBO with the inclusions of some amorphous carbon compound.

Phase state, chemical composition, and morphology of mechanically polished LiB3O5 surface are considered in comparison with as-grown (1 1 0) crystal face. Strong enriching of near surface layers with carbon is observed. A way to improve the polished LiB3O5 surface characteristics is demonstrated.Optical quality LBO crystals, 100x82x45mm3 in size, were grown by the TSSG method without pulling and rotating4. High pure powders of Li2CO3, B203, and MoO3 were used for flux preparation. As it was determined by X-ray powder

An area of CsLiB 6 O 10 K/%2 SKDVH HTXLOLEULXP LQ WKH &V 2 O-Li 2 O) -B 2 O 3 -MoO 3 system was determined with VSRQWDQHRXV FU\VWDOOL]DWLRQ PHWKRG &U\VWDOV RI oo 22 3 size have been growth in [100] direction with Kiropulos method. The forth-harmonic generation (270 nm) was achieved through the doubling of second-harmonic frequency in a multi-mode Nd:YAP laser in the type 1 collinear phase-matched geometry. The second-harmonic radiation in the technological laser of 3 mrad divergence was focused onto the input face of the crystal by a long-focus quartz lens. The input SRZHU GHQVLW\ RI WKH VHFRQG KDUPRQLF ZDV .:FP 2 . Using a 11.5 mm crystal, we showed that the highest efficiency of the forth-harmonic generation is 30%. The fifth harmonic (216 nm) in CLBO crystal was generated by composing the main laser beam and the forth-harmonic beam under the type 1 collinear phase-matching. Both beams were converged with dichroic and turning mirrors and then focused by a long-focus quartz lens. Our experiments showed that the fifth-harmonic generation in a multi-mode technological laser of 3 mrad divergence is possible in a 10 mm CLBO crystal of 23% optical FRQYHUVLRQ HIILFLHQF\ 7KH LQSXW SRZHU GHQVLW\ RI WKH IRUWK KDUPRQLF ZDV .:kf 2 . The use of longer CLBO crystal is less effective due to the nonlinear UV absorption and the walk off between the pump beam (1079 nm) and the harmonic beam.