Different experimental strategies towards the 3-dimensional photonic crystals operating at optical wavelength are classified. The detailed discussion is devoted to the recent progress in photonic crystals fabricated by template method — the photonic band gap materials on the base of opal. The control of photonic properties of opal-based gratings is achieved through impregnating the opal with high refractive index semiconductors and dielectrics. Experimental study demonstrated the dependence of the stop band behaviour upon the type of impregnation (complete or partial) and showed a way for approaching complete photonic band gap. The photoluminescence from opal- semiconductor gratings revealed suppression of spontaneous emission in the gap region with following enhancement of the emission efficiency at the low-energy edge of the gap.
Electromagnetic-wave propagation through dispersive and absorptive photonic-band-gap materials