Transparent polycrystalline YAG with nearly the same optical characteristics as those of a single crystal were fabricated by a solid‐state reaction method using high‐purity powders (>99.99 wt% purity). The average grain size and relative density of the 1.1 at.% Nd:YAG ceramics obtained were about 50 μm and 99.98%, respectively. An oscillation experiment was performed on a cw laser by the diode laser excitation system using the fabricated ceramics. The experimental results indicated an oscillation threshold and a slope efficiency of 309 mW and 28%, respectively. These values were equivalent or superior to those of the 0.9 at.% Nd:YAG single crystal fabricated by the Czochralski method.

Gold nanoparticles have been conformally coated with amorphous silica (using a sol-gel method) and then an organic polymer (via surface-grafted, atom transfer radical polymerization) to form spherical colloids with a core-double-shell structure. The thickness of silica and polymer shells could be conveniently controlled in the range of tens to several hundred nanometers by changing the concentration of the reagent and/or the reaction time. Selective removal of the silica layer (through etching in aqueous HF) led to the formation of hollow polymer beads containing movable gold cores. This new form of core-shell particles provides a unique system for measuring the feature size and transport property associated with hollow particles. In one demonstration, we showed that the thickness of a closed polymer shell could be obtained by mapping the electrons backscattered from the core and shell. In another demonstration, the plasmon resonance band of the gold cores was used as an optical probe to follow the diffusion kinetics of chemical reagents across the polymer shells.

Optical 3D alignment of nanocylinders has been successfully attained for thin films of a block copolymer (see figure) comprising azobenzene‐containing liquid‐crystalline polymers and poly(ethylene oxide) via photoinduced massive migration. The out‐of‐plane and in‐plane alignments are achieved by controlling the film thickness and selection of linear polarization direction upon illumination, respectively.