Dispersion characteristics of water- and gold-infiltrated opal photonic crystals

This paper presents a theoretical analysis of conditions for the propagation of electromagnetic waves in a wide frequency range (from the infrared to ultraviolet spectral region) in synthetic opals infiltrated with water and gold nanoparticles. A dispersion equation is derived which describes the dispersion law of both “right-hand” (right-hand system of the \(\vec E\), \(\vec H\), and \(\vec k\) vectors) and “left-hand” (left-hand system of the \(\vec E\), \(\vec H\), and \(\vec k\) vectors) electromagnetic waves in the crystals. We have determined the dispersion characteristics of the refractive index and broadband reflectance of the opals, group velocity dispersion, and effective mass dispersion for phonons and polaritons. Theoretical results are compared to measured reflection spectra.