WAVELENGTH DEPENDENCE OF 4-DIMETHYLAMINO-4'-NITROSTILBENE POLYMER THIN-FILM PHOTODEGRADATION

The polymeric electro-optical stilbene material, 4-dimethylamino-4 '-n itrostilbene (DANS), was illuminated at wavelengths ranging from the v isible to near-infrared in order to quantify its photodegradation proc esses. Photodegradation due to one-photon and two-photon absorption wa s studied. The quantum efficiency of the chromophore degradation is fo und to be strongly wavelength and absorption mechanism dependent. This suggests that, in different regions of the spectrum, different excite d states or different mechanisms are involved in the degradation proce ss. In the near-infrared spectral region, operation lifetimes of elect ro-optic devices made from this chromophore are expected to be around only few hundreds hours, dramatically shorter than it was previously b elieved. (C) 1998 American Institute of Physics.