Photochemically Controlled Photonic Crystals

• DOI: 10.1002/adfm.200304424
• Publication Date: 2003-10-08T10:03:25Z
• Authors: M. Kamenjicki; I.K. Lednev; A. Mikhonin; R. Kesavamoorthy; S.A. Asher
• Keywords: Azobenzene; Nanosecond; Microsecond; Visible spectrum; Millisecond

Abstract 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 the UV, visible, or near‐IR spectral regions. Information is recorded erased by exciting crystal with ∼ 360 nm UV light 480 visible light. The information read out measuring diffraction wavelength. active element of device an azobenzene‐functionalized hydrogel, which contains embedded crystalline colloidal array. excitation forms cis ‐azobenzene while trans ‐azobenzene. more favorable free energy mixing causes hydrogel to swell red‐shift diffraction. also observe fast nanosecond, microsecond, millisecond transient dynamics associated heating lattice constant changes, refractive index thermal relaxations.