Papers by Keyword: Photothermal Effect

Abstract: The photoisomerization of azobenzene (Azo) in system can induce changes of adhesion. Using this feature, some significant breakthroughs have been achieved in distinct adhesive systems from small molecular to polymer to supramolecular. Although the mechanisms vary from different situations, photoisomerization and photothermal effect of azobenzene under different irradiation always play significant role in the switch of the adhesion strength. By utilizing these features, some adhesive systems have illustrated promising and competitive performance. This review will concentrate on these achievements and advantages of photocontrolled adhesives based on azobenzene derivatives which are classified by photocontrolled mechanism. Furthermore, we also give some consideration to the future development of photocontrolled adhesives.

Abstract: Nonlinear light propagation in a dye-doped liquid crystal (LC) was investigated experimentally. A laser beam with wavelength far from the absorption peak of the material was coupled into an LC cell with homogeneous alignment, and the propagation in the cell was observed. When the polarization azimuth of the incident light was orthogonal to the orientation direction of the LC, soliton-like propagation was obtained for milliwatts of light power in spite of the low absorption. We clarified that the observed nonlinearity is due principally to the photothermal effect enhanced by the dye.

Abstract: Light propagation in an optical waveguide fabricated by employing a dye-doped liquid crystal (DDLC) was observed. The propagation of a light signal in the waveguide was varied by irradiation with a control light whose wavelength was in the absorption band of the DDLC. By considering the photothermal effect of the DDLC, which enables the change of the refractive index due to temperature variation based on the absorption of light, we qualitatively explained the observed light propagation and demonstrated manipulation of the propagation.