Photo-tunable PBG composite material was prepared by infiltration of the polymer liquid crystal (LC) having azo-chromophores in a SiO₂ inverse opal structure. The SiO₂ inverse opal film infiltrated with the polymer LC reflected a light, which is called Bragg diffraction, corresponding to the periodicity as well as the refractive indices of the inverse opal structure. Linearly polarized light irradiation caused the shift of the the Bragg diffraction band to longer wavelength more than 15 nm. This is caused by the formation of uniaxially anistorpic molecular orientation of the polymer LC. The switched state was stable under interior light, and reversible switching of the reflection band can be achieved by the linearly and circularly polarized light irradiation. This photoswitching property will be suitable for various optical materials such as memory, display so on.

Date Published: 12 October 2007
PDF: 9 pages
Proc. SPIE 6767, Photonic Crystals and Photonic Crystal Fibers for Sensing Applications III, 676707 (12 October 2007); doi: 10.1117/12.731308

Published in SPIE Proceedings Vol. 6767:
Photonic Crystals and Photonic Crystal Fibers for Sensing Applications III
Henry H. Du; Hiroshi Fudouzi, Editor(s)