Koichi Maeda

Optical performance of angle-dependent light-control glass

Angle dependent light control glass (LCG) is a new glass that scatters only incident lights from particular angles and transmits incident lights from all other angles. This unique light control function of LCG is caused by the microstructure in the specific polymer film sandwiched by a pair of glasses. The optical performance and properties described in this paper support that the principle of an angle dependent light control function can be explained mainly by diffraction due to the microstructure like a stack of various transmission volume phase gratings.

Control of Optical Properties of Thin Films Doped with Au Fine Particles by the Sol-Gel Method

We have developed tinted glasses with thin films doped with Au particles by the sol-gel method for automotive windows. Pink-colored glasses are mass-produced. The observed color is from absorption due to surface plasma resonance of Au particles. The squeeze-out of fine Au particles out of gel films was restrained by an organic additive. The index of the matrix was adjusted by the mixing ratio of TiO2 (refractive index n = 2.20) to SiO2 (n = 1.46). The absorption of Au particles is more intense with the higher index of the matrix, and its peak varies from 530 nm for n = 1.46 to 630 nm for n = 2.20, which yields a transmission color from pink to blue. The combination of the color of the glass substrate and the absorption by the Au particles in the thin films with various indices yields a variety of tinted glasses such as pink, orange, blue, blue-green and gray.

Optical properties of angle-dependent light-control film

Angle dependent light control film (LCF) is a new film which scatters only incident lights from particular angles and transmits incident lights from all other angles. This unique light control function of LCF is caused by the microstructure in itself. The optical performance and properties described in this paper support that the principle of an angle dependent light control function can be explained mainly by diffraction due to the microstructure like a stack of various transmission volume phase gratings.