Kamaljit Singh
Guru Nanak Dev University, India
Title: Nonlinear optical behaviour of thermally stable ferrocene based dyads and triads
Biography
Biography: Kamaljit Singh
Abstract
Nonlinear optical (NLO) responsive materials are of great interest for applications related to photonics, nanophotonics and optoelectronics, such as integrated optics, optical sensing, optical signal processing, optical computing, broad band optical communications, optical poling, optical limiting, etc. We recently described NLO behaviour of tetrathia[22]porphyrin(2.1.2.1)s, which depict reverse saturable absorption.1
In continuation of our interest in designing ferrocene (Fc) based materials2 for NLO applications, two sets of new Fc based chromophores were synthesized and their optical, NLO and electrochemical properties were investigated. The second-order nonlinear polarizabilities were determined using hyper-Rayleigh scattering (HRS) with femtosecond pulsed laser light at 840 nm. The dyads exhibit interesting structure-dependent NLO properties, which could be rationalized by correlating optical with electrochemical data. For example, the dyad3 with strongest (formyl) acceptor group in combination with the longer conjugation path between this acceptor and the Fc donor, showed the largest static hyperpolarizability value, as compared to dyads with shorted conjugation and/or weaker acceptors. A partially symmetrical and longer triad showed the longest absorption wavelength, yet the smallest dipolar properties (dipole moment and first hyperpolarizability), due to partial cancellation, in agreement with symmetry correlations.