Diffraction of obliquely incident light at oblique helicoidal cholesteric

We demonstrate experimentally that diffraction of light incident obliquely at the oblique helicoidal cholesteric (ChOH) structure results in scattering at both the half- (P/2) and the full pitch (P) periodicities. Transmission spectra at P and P/2 are observed in the Vis spectral range, tunable by the electric field and the angle of light incidence. Diffraction at P/2 shows two distinct spectral bands for p- and s-polarized incident light. Diffraction at P is a single wide band. Unique optical properties of ChOH are attractive for applications such as electrically tunable band-pass filters, optical rotators, and beam-steering devices.