Articolo in rivista, 2008, ENG, 10.1088/1464-4258/10/5/055301

Electrical reorientation of liquid crystal molecules inside cylindrical pores for photonic device applications

V. Tkachenko 1,2; A.A. Dyomin 3; G.V. Tkachenko 3; G. Abbate 1,2; I.A. Sukhoivanov 4

1 Univ Naples Federico 2, CNR, INFM Coherentia, I-80126 Naples, Italy; 2 Univ Naples Federico 2, Dept Phys Sci, I-80126 Naples, Italy; 3 Kharkov Nat Univ Radio Elect, UA-61166 Kharkov, Ukraine; 4 Univ Guanajuato, FIMEE, Salamanca 36730, Mexico

We present the simulated distribution of the local director of a nematic liquid crystal inside cylindrical macropores under the influence of an electric field. The Frank free energy approach is used to describe the nematic behavior. The influence of both molecular anchoring strength and pore radius is investigated. The results of this analysis are applied for simulation of an electrically tunable microcavity based on porous silicon infiltrated with a liquid crystal. The Bruggeman approximation is used while calculating the effective refractive index of each layer in the porous silicon multilayer structure. The reflectivity spectrum of the latter is simulated using the transfer matrix approach. The electrical tuning range of a microcavity designed for near-infrared waves is found to vary from 10.5 up to 23 nm for weak and strong surface anchoring conditions, respectively.

Journal of optics. A, Pure and applied optics (Print) 10 , pp. 055301-1–055301-6

Keywords

liquid crystal, director reorientation, refractive index, porous silicon, tunable microcavity

CNR authors

Abbate Giancarlo, Tkachenko Volodymyr

CNR institutes

SPIN – Istituto superconduttori, materiali innovativi e dispositivi