Encoding of macroscopic second-order son-linearity via all-optical polar alignment in substituted norbornene polymer thin films

Efficient all-optical poling of substituted norbornene ate-molecules-doped polymer thin films is presented. The growth and decay of photoinduced secon d-order susceptibility chi ((2)) has been studied. The possibility of encod ing chi ((2)) at low seeding intensities (about 10 MW/cm(2) for fundamental and 100 W/cm(2) for second harmonic) is demonstrated. The value of encoded chi ((2)) in mono-norbornene-doped polymethylmethacrylate (PMMA) and poly- norbornene polymer have been found to be with the same order of magnitude d espite the latter revealed considerably higher first hyperpolarizability. T his is due to the rigidity of the poly-norbornene polymer backbone and the strong orientational correlation between pendant chromophores that reduce r eorientation of molecules. (C) 2000 Elsevier Science B.V. All rights reserv ed.