Structural characterization of thin film photonic crystals

G. Subramania, Iowa State University
Rana Biswas, Iowa State University
Kristen P. Constant, Iowa State University
M. M. Sigalas, Iowa State University
Kai-Ming Ho, Iowa State University

This article is from Physical Review B 63 (2001): 1, doi: 10.1103/PhysRevB.63.235111. Posted with permission.

Abstract

We quantitatively analyze the structure of thin film inverse-opal photonic crystals composed of ordered arrays of air pores in a background of titania. Ordering of the sphere template and introduction of the titania background were performed simultaneously in the thin film photonic crystals. Nondestructive optical measurements of backfilling with high refractive index liquids, angle-resolved reflectivity, and optical spectroscopy were combined with band-structure calculations. The analysis reveals a thin film photonic crystal structure with a very high filling fraction (92–94 %) of air and a substantial compression along the c axis (∼22–25%).