Temperature-dependent electronic dephasing of molecules in polymers in the range 30 to 300 K

The ultrafast electronic dephasing of the molecules LD690 and LDS750 dissolved in amorphous polymer hosts is examined in the temperature range 30–300 K. The polarization decay time of LD690 in PMMA and PVA varies from about 40 fs at room temperature to 160 fs at 28 K, while the decay of LDS750 in PMMA is close to pulsewidth-limited at all temperatures. The difference between the dynamics observed in these two molecules shows how the molecular nature of the solute can affect the observed dephasing dynamics.