title: Electric field poled polymeric nonlinear optical systems: molecular dynamics simulations of poly(methyl methacrylate) doped with disperse red chromophores.
abstract: We demonstrate a complete procedure for simulations of electric field poled polymeric nonlinear optical systems with the purpose to evaluate the macroscopic electro-optic coefficients. The simulations cover the electric field poling effects on the chromophore order at the liquid state, the cooling procedure from the liquid to the solid state in the presence of the poling field, and the back-relaxation of the system after the removal of the field. We use Disperse Red chromophore molecules doped in a poly(methyl methacrylate) matrix for a numerical demonstration of the total procedure. On the basis of the simulation results, the polymer mobility and the static properties of the dopant chromophores are derived. In the liquid state, the chromophore molecules are closer to the side chains than to the backbones of the polymer matrix, and after the simulated annealing, the polymer matrix tends to be closely packed, leading to a significant change in the polymer structure around the chromophore molecules. Besides predicting the absolute macroscopic electro-optic coefficient values, the results are used to derive the microscopic origin of these values in terms of geometric and electronic structure, loading, poling, and back-relaxation effects, thereby aiding to establish design principles for optimum guest-host configurations.
authors: Theoretical Chemistry, Royal Institute of Technology, AlbaNova University Center, S-106 91 Stockholm, Sweden.
authors: Yaoquan
authors: Y
authors: Tu
authors: Qiong
authors: Q
authors: Zhang
authors: Hans
authors: H
authors: Agren
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003198:Computer Simulation; D004574:Electromagnetic Fields; D015394:Molecular Structure; D055095:Optics and Photonics; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors
chemical_list: D001391:Azo Compounds; C069318:Disperse Red 1; D019904:Polymethyl Methacrylate