Ultrafast photo-induced shift of transmission dip in distributed feedback cavity with exciton resonance

Femtosecond pump-probe spectroscopy is performed on a distributed feedback cavity, in which the layered perovskite semiconductor, (C/sub 6/H/sub 5/C/sub 2/H/sub 4/NH/sub 3/)/sub 2/PbI/sub 4/, is embedded. It is found that, by pumping the exciton resonance, the guided wave mode is shifted to higher energy.