titania

Inhibited light propagation and broad band reflection in photonic air-sphere crystals
M. S. Thijssen, R. Sprik, J. E. G. J. Wijnhoven, M. Megens, T. Narayanan, A. Lagendijk, and W. L. Vos
Phys. Rev. Lett. 83, 2730-2733 (1999)

Preparation of photonic crystals made of air spheres in titania
J. E. G. J. Wijnhoven and W. L. Vos
Science 281, 802-804 (1998)