L‐6: Late‐News Paper : Achromatic Diffraction Using Reactive Mesogen Polarization Gratings

We propose and experimentally demonstrate an achromatic polarization grating, with ∼100% diffraction efficiency over nearly the entire visible spectral range. This five‐fold enhancement (∼34.3% versus ∼6.8%) is produced by two chiral liquid crystal layers with modest twist angle and opposite twist sense. Finite‐difference time‐domain (FDTD) simulations support the experimental phenomena.