Relaxation processes in poled nonlinear optical polymers

The orientation and deorientation of polar chromophores in nonlinear optical polymers are often described in terms of a free-rotation model that allows for only two main relaxation times. In reality, however, glassy polymers are characterised by a broad distribution of relaxation times. Theoretical functions for the rise and the decay of the dipole orientation in polymers and their connections with macroscopic observables are discussed. In addition, experimental results obtained with various techniques on a typical side-chain polymer are given and shown to be essentially identical.