Journal of the Physical Society of Japan
Ultrafast Dephasing and Incoherent Light Photon Echoes in Organic Amorphous Systems
Ryuzi Yano, Yoshinori Matsumoto, Toshiro Tani, Hiroki Nakatsuka
Abstract
Incoherent light photon echoes were observed in organic amorphous systems (cresyl violet in polyvinyl alcohol and 1,4-dihydroxyanthraquinone in polymethacrylic acid) by using temporally-incoherent nanosecond laser pulses. It was found that an echo decay curve of an organic amorphous system is composed of a sharp peak which decays very rapidly and a slowly decaying wing at the tail. We show that the persistent hole burning (PHB) spectra were reproduced by the Fourier-cosine transforms of the echo decay curves. We claim that in general, we must take into account the multi-level feature of the system in order to explain ultrafast dephasing at very low temperatures.