Local reflection micro-spectroscopy of excitons in fibril-shaped molecular J-aggregates prepared in PVA thin films

Results on microscopic reflection imaging and spectroscopy of fibril-shaped J-aggregates of pseudoisocyanyne dyes prepared in thin film matrices of polyvinyle alcohol (PVA) are reported. We have found that formation of fibril-shaped structures with sub-micron widths is also possible in PVA. Despite the aggregation mechanism should be different from those in polyvinyl sulfate, reflection images and local spectroscopy show that the exciton–polariton characters are basically similar in the two matrices. Anomalous polarization dependence is also observed in PVA and seems rather strengthened.