We gratefully acknowledge financial support from ONR, NSF, and DARPA.
Photochemically Controlled Photonic Crystals†
Article first published online: 7 OCT 2003
Copyright © 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Advanced Functional Materials
Volume 13, Issue 10, pages 774–780, October, 2003
How to Cite
Kamenjicki, M., Lednev, I.K., Mikhonin, A., Kesavamoorthy, R. and Asher, S.A. (2003), Photochemically Controlled Photonic Crystals. Adv. Funct. Mater., 13: 774–780. doi: 10.1002/adfm.200304424
- Issue published online: 7 OCT 2003
- Article first published online: 7 OCT 2003
- Manuscript Accepted: 19 JUN 2003
- Manuscript Received: 27 MAY 2003
- Photonic crystals;
- Photoresponsive materials
We have developed photochemically controlled photonic crystals that may be useful in novel recordable and erasable memories and/or display devices. These materials can operate in the UV, visible, or near-IR spectral regions. Information is recorded and erased by exciting the photonic crystal with ∼ 360 nm UV light or ∼ 480 nm visible light. The information recorded is read out by measuring the photonic crystal diffraction wavelength. The active element of the device is an azobenzene-functionalized hydrogel, which contains an embedded crystalline colloidal array. UV excitation forms cis-azobenzene while visible excitation forms trans-azobenzene. The more favorable free energy of mixing of cis-azobenzene causes the hydrogel to swell and to red-shift the photonic crystal diffraction. We also observe fast nanosecond, microsecond, and millisecond transient dynamics associated with fast heating lattice constant changes, refractive index changes, and thermal relaxations.