Photonic band-gap structure: From spectroscopy towards visualization

Abstract

We determined the photonic band-gap structure of synthetic opals by combining the measured angle-resolved transmission spectra and optical frequency-resolved diffraction patterns. The latter were observed as symmetrical sets of spots, each being a colored fingerprint of the photonic band gap for a certain direction. The spot color gives information about the energy of the band gap, while the angular spot position on the screen informs of the direction along which the band gap occurs. Our results provide a basis for three-dimensional light control by photonic crystals.