Microsecond-response high pixel-per-inch (PPI) amplitude and phase modulation with low driving voltage are in high demand for abounding modern applications, ranging from virtual reality (VR), augmented reality (AR), hologram, and wavelength selective switch (WSS), and so forth. However, bottlenecks still exist, such as slow response, limited PPI due to fringe field effect (FFE) and the integrated circuit (IC) driving backplane, poor contrast ratio (CR), bulky size and exorbitant price. Fast switching ferroelectric liquid crystal (FLC) without FFE is a promising hope to achieve fast (~100 μs) and high PPI ( 10000) devices with continuous 2π phase modulation range. 5 key achievements are included in this thesis. Firstly, a new dynamic model describing the entire unwinding process of FLC i...[ Read more ]

Microsecond-response high pixel-per-inch (PPI) amplitude and phase modulation with low driving voltage are in high demand for abounding modern applications, ranging from virtual reality (VR), augmented reality (AR), hologram, and wavelength selective switch (WSS), and so forth. However, bottlenecks still exist, such as slow response, limited PPI due to fringe field effect (FFE) and the integrated circuit (IC) driving backplane, poor contrast ratio (CR), bulky size and exorbitant price. Fast switching ferroelectric liquid crystal (FLC) without FFE is a promising hope to achieve fast (~100 μs) and high PPI (> 10000) devices with continuous 2π phase modulation range. 5 key achievements are included in this thesis. Firstly, a new dynamic model describing the entire unwinding process of FLC is constructed and verified. Compared with the traditional model, a newly proposed FLC dynamic model involves not only the unwinding process in a large voltage range but also the frequency dependence of Electro-optical (EO) performance by introducing dielectric anisotropy. Apart from that, the TFT requirement for driving FLC is evaluated based on the proposed FLC model. Secondly, the designed FLC device also shows fast response, and high CR ascribe to optimization in the density of the spacers and the recipe of the alignment layer. Thirdly, deformed helix ferroelectric liquid crystals (DHFLC) with subwavelength pitch show no pixel expansion and disclination lines, which is an important feature in suppressing the FFE. That is to say, the proposed no-FFE panel can achieve PPI up to 10000. Finally, a fast continuous 2π phase modulation using defect-free DHFLC is proved. Innovatively, continuous phase modulation with 2π phase depth, > 10000 PPI, fast switching, low driving voltage (< 5 V) and no-ellipticity is achieved based upon DHFLC for the first time. This system is a promising candidate for various state-of-art technology.