Design and synthesis of novel H-Shaped chromophore for enhanced nonlinear optical properties

摘要

A novel H-shaped nonlinear optical chromophore B based on julolidinyl donors were designed and synthesized through Williamson ether reaction. The chromophore B is composed of two traditional rod-shaped chromophores A linked to each other through an isolation group, forcing chromophore separation through steric interaction. Chromophore B showed good thermal stability and film-forming ability. Besides, the reduction of intermolecular electrostatic interactions allows for increased active chromophore number density in the formulation of a host-guest doping material, thus enhancing electro-optic response. Polymers doped with 35 wt% chromophore B have been poled to afford large electro-optic coefficient (r(33)) of 180 pm/V at 1310 I1M, which is nearly two times higher than that obtained from the chromophore A (92 pm/V) at the doping concentration of 25 wt%. These results indicated that the H-shaped chromophore B has the advantages over rod-shaped chromophore A in transforming the microscopic hyperpolarizability into a macroscopic electro-optic coefficient.