Probing Local Environments by Time-Resolved Stimulated Emission Spectroscopy

Table 1

Stimulated emission decay times and relative amplitudes for various different water : glycerol mixtures and for the sol-gel matrix at the different probe wavelengths. A negative amplitude indicates a rising rather than a decaying component. The sol-gel data could be fitted to a single exponential function with a residual amount around 25–30% that did not decay in the time window of the experiment. The viscosity values are taken from [28].

Sample	Probe λ (nm)	τ1 (ps)	α1	τ2 (ps)	α2	τ3 (ps)	α3
Water (0.89 cp)	560			0.53	1
	580			0.67	0.59	9.86	0.41
	600	0.25	−1	0.57	0.54	8.46	0.46
	620	0.2	−1			12.1	1
Glycerol 40% (3.18 cp)	560			7.91	1
	580			1.7	0.59	34.3	0.41
	600	6.0	−1	6.1	0.41	69.9	0.59
	620	5.1	−1	8.3	0.60	38.5	0.40
Glycerol 80% (45.9 cp)	560			14.2	1
	580			18.9	0.12	255.7	0.88
	600					203.2	1
	620	4.73	−1			254	1
Sol-gel	560					84	0.73
	580					91	0.74
	600					128	0.75
	620					186	0.70