Disorder induced modification of reflection and transmission spectra of a two-dimensional photonic crystal with an incomplete band-gap

Transmission and reflection of light in disordered two-dimensional photonic crystals with an incomplete photonic band-gap have been modelled for various levels of disorder. It is found that ballistic and scattered light display different behaviours as a function of the disorder parameter. For ballistic light, the dependence of the transmission coefficient on the disorder parameter exhibits a threshold-like behaviour, whereas the transmission of scattered light increases rapidly for small disorder. Unlike for photonic crystals with a complete bandgap, the minimum of the transmission for scattered light does not coincide with the centre of the photonic band-gap, and Fabry-Perot-type oscillations can be seen within the photonic band-gap.