Low-Threshold-Voltage and Electrically Switchable Polarization-Selective Scattering Mode Liquid Crystal Light Shutters

• Published in: Polymers Vol. 10; no. 12; p. 1354
• Main Authors: Liang, Zhe-Yung, Tu, Ching-Yen, Yang, Tsung-Hsun, Liu, Cheng-Kai, Cheng, Ko-Ting
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 06.12.2018; MDPI
• Subjects: Electric fields; Electric potential; Electrodes; Glass substrates; Light; Light scattering; Liquid crystals; Motion picture directors & producers; Nematic crystals; Polarization; Polymers; Response time; scattering; Shutters; Voltage; polarization; liquid crystals; polymers; scattering
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym10121354

Low-threshold-voltage (V ) and electrically switchable, polarization-selective scattering mode light shutters (PSMLSs) using polymer-dispersed liquid crystals (PDLCs) are demonstrated in this work. The optimized weight ratio of the nematic liquid crystals (LCs) to the adopted monomer (NBA107, Norland Optics) in the low-V PDLCs based on NBA107 is 7:3, [7:3]-PDLCs . The properties of the low-V PDLCs , such as light-scattering performance, initial transmission, V , and droplet size were investigated. Experiment results show that the surface anchoring (threshold-voltage) of NBA107 is weaker (lower) than or equal to that of the common NOA65. The cost is that the response time of the proposed PDLCs is relatively long. A method to reduce the decay time, which can be applied to all other PDLC devices, will be elucidated. In addition to the low V of the proposed PDLCs , the operation voltage (~6 V ) to approach the maximum transmission is relatively low in a 7 μm-thick PDLCs cell. Moreover, the polarization-selective light-scattering performances of the proposed PSMLSs based on the [7:3]-PDLCs , mainly driven by in-plane and vertical fields, are also demonstrated.