Nonlinear optical chromophores and polymers for practical electro-optic waveguide application

Among the many physical properties of organic nonlinear optical (NLO) chromophores that require optimization, their generally inadequate thermal stability has recently attracted significant attention. Here we describe protocols for the evaluation of the thermal stability of chromophores that may be employed prior to their incorporation into a device environment. These protocols involve a variety of conventional analytical techniques including thermal analysis (TGA, DSC) and electrochemistry (CV) that have led to the identification of the most facile thermal decomposition process of the widely utilized family of 4-amino-4'-nitroazobenzene NLO dyes. Knowledge of the decomposition mechanism has facilitated implementation of structural modifications in the amine donor of these dyes that deliver enhanced thermal stability. It is anticipated that these protocols and structure modifications are of general relevance.