Third-order nonlinear optical properties of in-backbone substituted conjugated polymers

We present an alternative approach to tune the third-order nonlinear optical properties of organic molecules by inserting a functional group into the path of the pi-electron conjugation instead of at its ends. We show that this scheme has a beneficial influence on the second-order hyperpolarizability for short molecules, but that in two instances where such molecules were polymerized into longer molecules the overall hyperpolarizability is reduced. (C) 2002 American Institute of Physics.