Optically excited secondary emission spectra of photonic crystals based on synthetic opals

The photonic dispersion, the group-velocity dispersion, the effective mass, refractive index, and the spectral distribution of the density of photonic states near the edge of the photonic stop band are numerically calculated in the one-dimensional model for photonic crystals based on synthetic opals. The fluorescence spectra of rhodamine 6G and 2,5-bis(2-benzoxazolyl)hydroquinone molecules infiltrated into a synthetic opal are measured. For both substances, it is observed that the spontaneous emission intensity in the range of the photonic stop band is appreciably suppressed. A blue shift of the fluorescence spectrum of rhodamine 6G molecules is revealed. Secondary emission of synthetic opals infiltrated with colloidal silver is observed in the Stokes range under excitation of opals by radiation at λ = 400 nm. The spectrum of the secondary emission is located in the range 450–590 nm, which contains the stop band and intervals near its edges.