Polarization conversion by a three-dimensional photonic crystal mirror with a diamond structure

We report experimental and numerical studies of a polarization conversion by a three-dimensional photonic crystal. The (0 0 1) surface of a photonic crystal with a diamond structure has been shown to act as a mirror-type polarization convertor under normal incidence. When the direction of the incident wave polarization is along [0 1 0], the direction of the reflected wave polarization is converted to [1 0 0]. This has been found to be due to approximately a half-wave phase shift between the eigenpolarizations of [1 1 0] and [1 1¯ 0] upon reflection. This result has been discussed in relation with a polarization-dependent Goos–Haenchen effect.

► A diamond photonic crystal acts as a mirror-type polarization convertor.
► This is due to a phase shift between two eigenpolarizations upon reflection.
► The phase shift is caused by a positional shift of the evanescent fields.
► This is a kind of polarization-dependent Goos-Haenchen effect.