Emission stability and high current performance of diamond-coated Si emitters Effects of native oxide removal from silicon substrate and annealing on SiO2 films deposited at 120 °C by plasma enhanced chemical vapor deposition using disilane and nitrous oxide

In-plane electro-optical switching (IPS) is a natural feature of a conventional planar-aligned display cell based on the deformed helix ferroelectric liquid crystal effect (DHFLC-effect) with a sub-wavelength helix pitch, if the tilt angle is close to 40 degrees.

We report the development of chiral smectic C* (SmC*) ferroelectric materials with a short helix pitch p o < 150 nm obtained by mixing a nematic liquid crystal (NLC) and chiral non-mesogenic dopants. Chiral dopants are optically active lactates based on terphenyldicarboxylic acid, and the NLC is a binary eutectic mixture of phenyl-and biphenylpyrimidines. The appearance of the SmC* phase in mixtures was confirmed by dielectric, optical and electro-optical measurements. The proposed method for the elaboration of smectic C* material makes it possible to create innovative electro-optical media that combine the mechanical stability of NLC and a high switching frequency of ferroelectric liquid crystals. The high twisting power of chiral lactates in the developed nematic matrix made it possible to obtain a satisfactory optical quality of induced SmC* in electrooptical cells that can efficiently operate up to frequency of 3 kHz.

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Extraction of spectral information using liquid crystal (LC) retarders has recently become a topic of great interest because of its importance for creating hyper- and multispectral images in a compact and inexpensive way. However, this method of hyperspectral imaging requires thick LC-layer retarders (50 µm–100 µm and above) to obtain spectral modulation signals for reliable signal reconstruction. This makes the device extremely slow in the case of nematic LCs (NLCs), since the response time of NLCs increases proportionally to the square of the LC-layer thickness, which excludes fast dynamic processes monitoring. In this paper, we explore two approaches for solving the speed problem: the first is based on the use of faster nanospiral ferroelectric liquid crystals as an alternative to NLCs, and the second is based on using a passive multiband filter and focuses on multispectral extraction rather than hyperspectral. A detailed comparative study of nematic and ferroelectric devices is presented. The study is carried out using a 9-spectral bands passive spectral filter, covering the visible and near-infrared ranges. We propose the concept of multispectral rather than hyperspectral extraction, where a small number of wavelengths are sufficient for specific applications.