Babayan E A, Budagovsky I A, Shvetsov S A, Smayev M P, Zolot'ko A S, Boiko N I, Barnik M I
P. N. Lebedev Physical Institute, Russian Academy of Sciences, Leninsky pr. 53, 119991 Moscow, Russia.
Phys Rev E Stat Nonlin Soft Matter Phys. 2010 Dec;82(6 Pt 1):061705. doi: 10.1103/PhysRevE.82.061705. Epub 2010 Dec 22.
Interaction of light and ac electric fields with a nematic liquid crystal (NLC) doped with nanosized second-generation carbosilane codendrimers containing terminal azobenzene fragments has been studied. A first-order Freedericksz transition in the linearly polarized light, accompanied by an intrinsic bistability in a wide region, was observed. An additional ac electric field decreases the light-induced Freedericksz transition threshold and narrows the bistability region. Light illumination transforms the second-order electric-field-induced Freedericksz transition to a first-order one. The width of the bistability region increases with the light wave intensity. The theory of the interaction of light and ac electric fields with the dendrimer-doped NLCs is developed taking into account an additional (with respect to the undoped nematic host) dependence of the optical torque on the angle between the director and the light field.
研究了光和交流电场与掺杂有含末端偶氮苯片段的纳米尺寸第二代碳硅烷共聚物树枝状大分子的向列型液晶（NLC）之间的相互作用。观察到线性偏振光中的一阶弗雷德里克兹转变，伴随着在宽区域内的固有双稳性。额外的交流电场降低了光诱导的弗雷德里克兹转变阈值并缩小了双稳性区域。光照将二阶电场诱导的弗雷德里克兹转变转变为一阶转变。双稳性区域的宽度随光波强度增加。考虑到（相对于未掺杂的向列型主体）光学扭矩对指向矢与光场之间角度的额外依赖性，建立了光和交流电场与树枝状大分子掺杂的NLC相互作用的理论。
