Evolution of optical diffraction patterns on disordered woodpile photonic structures

Using three-dimensional direct laser writing, ordered and disordered photonic woodpile structures have been produced. An ideal woodpile is formed by layers of parallel “logs” turned through 90$^{\circ}$ with respect to logs of the previous layer. The disorder was specified by a random deviation in the angle with respect to their parallel arrangement in each layer of the woodpile. The quality of samples was tested by scanning electron microscopy. The optical diffraction patterns were studied experimentally on microsamples with different degrees of disorder and structure periods. With an increase in the degree of the disorder, the diffraction patterns changed qualitatively with the preservation of the zero diffraction order and formation of a speckle field pattern by higher diffraction orders.