Reflection Spectra of Bare and Infiltrated with Ba(NO3)2 Synthetic Opal Photonic Crystals

Angular dependences of Bragg reflection spectra for the bare and infiltrated synthetic opal photonic crystals of Ba(NO3)2 have been studied in the wavelength range of 420–630 nm for the geometry of specular reflection and the incidence angles 5?, 20?, 30? and 45?. Theoretical relation between the diffracted light wavelengths at the maximum reflectance and the angle of incidence has been used and compared with the experimental one. The distance between (111) planes of opal and the diameter of silica globules have been determined. Angular distribution of diffuse reflection has been measured in the vicinity of direction of specular reflection.