All-optically controllable and highly efficient scattering mode light modulator based on azobenzene liquid crystals and poly(N-vinylcarbazole) films

作者：Liu Yen Chen; Cheng Ko Ting; Chen Yuan Di; Fuh Andy Ying Guey^*

来源：Optics Express, 2013, 21(15): 18492-18500.

DOI：10.1364/OE.21.018492

The present study reports that isothermal phase transition induced by photoisomerization of azobenzene liquid crystals (azo-LCs) from trans-to cis-isomers results in the dissolution of poly(N-vinylcarbazole) (PVK) into azo-LCs. Transparent (scattering) states can be demonstrated using uniform (rough) morphologies of PVK generated by slow (rapid) phase separation of PVK and azo-LCs from cis- to trans-isomers. The PVK films were examined in detail using scanning electron microscopy. Scattering performance resulting from the rough PVK surface induced micron-sized LC domains, and transparent performance resulting from the reformed uniform PVK surface can be optically and reversibly switched. Finally, all-optically controllable and highly efficient (contrast ratio of 370: 1) scattering mode light modulators based on azo-LCs and PVK films were demonstrated.

• 出版日期2013-7-29
• 单位中央民族大学