No abstract

Here we disclose a fast (ON time ∼50 μs and OFF time ∼25 μs at 55 °C), high‐contrast, continuous phase modulator without fringe field effect (FFE). The phase modulator uses the Kerr effect of vertically aligned deformed helix ferroelectric liquid crystals (VADHFLCs). Specifically, FFE is a long‐term problem for nematic liquid crystals (NLCs). In this article, we are disclosing, for the first‐time found, that no FFE exists for VADHFLCs, even for phase modulator with 1‐μm pixel pitch. It is an attractive feature for ultra‐high‐resolution display and photonic applications. Moreover, the Kerr constant is 88 nm/normalV2, and the contrast ratio is larger than 1000:1. It is a promising candidate for high‐PPI augmented reality (AR)/virtual reality (VR) displays, wavelength selective switch (WSS), hologram, adaptive optics, and LiDARs.

In this work, a combined system including FLC high‐speed polarization rotator, liquid crystal polymerizable polarization grating, FLC switchable Dammann Grating is proposed to form tunable diffractive spot matrices and acquire depth information. By adjusting electric field, the grating can be switched between diffractive state showing 4 by 4 optical spots arrays in two areas and non‐diffractive state, respectively. At a low driving voltage of 5V, our approach renders the gratings electrically tunable with a fast response time of 50μs, which has the potential for LiDAR applications.