Stoichiometric Mg:LiNbO(3) as an effective material for nonlinear optics

Photorefractive damage, optical absorption, photoconductivities, and photogalvanic currents of stoichiometric LiNbO(3) single crystals with different Mg doping levels have been investigated. Nominally pure stoichiometric LiNbO(3) shows lower photorefractive damage resistance than congruent crystal; however, stoichiometric crystals doped with MgO of more than 1.8 mol. % exhibit no measurable photorefractive damage at 532 nm to intensities of as much as 8 MW/cm(2) . This remarkable damage resistance can be attributed not only to increased photoconductivity but also to decreased photogalvanic current. Stoichiometric Mg:LiNbO(3) also demonstrates the shortest absorption edge, 302 nm, and a single-domain nature with low scattering losses.     

Space- and time-resolved spectroscopic analyses in micrometre dimensions

Space- and time-resolved microspectroscopies have been developed and applied to the study of inhomogeneous structures in two-dimensional (microtubes and microchannels) and three-dimensional samples (polymer microspheres and microdroplets). In this particular technique, an optical trapping method was applied successfully to elucidate the chemical and physical characteristics of individual microparticles in solution. Confocal fluorescence microspectroscopy was also shown to have sufficient potential to observe directly the ion-exchange–diffusion processes of an ion in single ion-exchange polymer microparticles. The important roles of space- and time-resolved microspectroscopy in analysing several minute samples having different sizes and shapes are described in detail.     

(S)‐4‐Benzyl‐3‐[(R)‐4,4,4‐tri­fluoro‐3‐(4‐methoxy­phenyl)­butanoyl]‐1,3‐oxazolidin‐2‐one

The C atom at the chiral centre of the title compound, C₂₁H₂₀F₃NO₄, takes an R configuration. From this assignment, useful information on the intermediate process of the reaction was deduced.