Titania inverse opals for infrared optical applications

Photonic crystals have gathered great importance in recent years. In partic ular macroporous materials (inverse opals) show interesting properties as p hotonic crystals. Ordered macroporous titanium dioxide (TiO2) is made using polystyrene spheres as a template. Titania is chosen for its high refracti ve index (>2.5). Following an already known technique [E.G. Judith, J. Wijn hoven, W.L. Vos, Science 281 (1998) 802; B.T. Holland, C.F. Blanford, A. St ein, Science 281 (1998) 538; B.T. Holland, C.F. Blanford, T. Do, A. Stein, Chem. Mater. 11 (1999) 795] large-scale order in macroporous TiO2 is obtain ed both using the 778 and the 3190 nm beads as documented by optical micros cope and SEM images. These structures would lead to applications in the mid -infrared range. (C) 2001 Elsevier Science B.V. All rights reserved.