Third-Order Nonlinear Optical Response of a New Linear Polymer With 4-Aminoazobenzene

Abstract

Nonlinear refraction in a new polymer material based on diglycidylether of bisphenol-A and containing 4-aminoazobenzene covalently attached to the polymer chains have been studied. The material was shown to exhibit fast nonlinear response (relaxation time about 20 ns, χ(3)= 5 × 10- 8 esu) together with slow one (relaxation time of the order of tens of hours). This makes it possible to record fast and long life (quasi stationary) phase holograms. An analysis of possible mechanisms for the refractive index nonlinear behavior in the new structure is presented. In particular, a role of electronic, thermal, orientation, and isomerization processes is discussed. It was for the first time shown that the rotational and inversion mechanisms of the cis → trans isomerization of the azo-compounds have determinative effect upon kinetics of the nonlinear refractive index relaxation. For the rotational mechanism the relaxation time was found to be 10-4 s meanwhile for the inversion mechanism it was 105 s.

Periodic decay in the photoisomerisation of p-aminoazobenzene

“…We focus on pAAB which serves as a simple model system for more complex molecules that have recently been reported. [46][47][48] By comparing pAAB with AB we can assess how amino substitution may affect and possibly control the outcome of the photoreaction. As in the case of AB, 37,38 we also explore the role of specific vibrational modes in pAAB photoisomerisation, noting that vibrational control has already been invoked in other photoreactions.…”

Third‐order optical nonlinearity of azobenzene side‐chain polymer thin film

“…From the viewpoint of practical values, polymer materials are expected to overcome the disadvantage of organic molecular crystals in mechanical properties and processability. The experimental results show that azo dye molecules DR1 attached to a polymer have greatly increased the length of π → π* conjugation [16].…”