Project Description

Nonlinear optics has been the subject of intensive research, because of its wide applications in the field of photonics, optoelectronics, optical communications and signal processing etc. In particular, the second order nonlinear optical (NLO) properties of organometallic chromophores are mostly reported in one-dimensional dipolar push-pull molecules with donor-π-acceptor (D-π-A) structure. However, it often crystallizes in centrosymmetric crystal lattice due to the antiparallel alignment which results weak or zero NLO effect. To overcome, chirality, π-extended conjugation, H-bonding functionalities and steric effect (multidimensional X-, Y-, V-, T- and H-shaped) can be introduced in the backbone reduces the possibility of a head-to-tail orientation by electronic D-D and A-A repulsions, result optimal NLO response. The solid state SHG efficiencies in bulk will be measured using Kurtz and Perry powder technique, and the solution state molecular hyperpolarizability (β) will be carried out by Hyper-Rayleigh Scattering (HRS) or Electric Field-Induced Second Harmonic (EFISH) generation techniques. The density functional theory (DFT/TD-DFT) will be applied to validate the optical and nonlinear optical properties at molecular level.