Broadening of the S2-S0 luminescence spectrum of a rhodamine 6G solution during intense laser excitation
Galanin M. D. , Chizhikova Z. A.
An intense spectral broadening has been observed in the luminescence from the second excited electronic state, S2, of the rhodamine 6G molecule at an excitation intensity ΙΟ29—1030 photons/(cm2-s). This broadening is attributed to a buildup of vibrational energy when the average time between excitation events is shorter than the vibrational relaxation time rr. This relaxation time is estimated to be rr=(3±l)XlO-13 s.