Heterogeneous relaxation patterns in supercooled liquids studied by solvation dynamics

We have measured the solvation dynamics of a dipolar supercooled liquid nea r its glass transition in a temperature range in which the average structur al relaxation time varies more than four orders of magnitude. The analysis of the time dependent average emission energy and the inhomogeneous linewid th of the S-0 <--T-1(0-0) transition reveals that the orientation correlati on decay pattern intrinsic in each relaxing unit is associated with a stret ching exponent beta(intr) = 1.00 +/- 0.08 in the entire range T-g less than or equal to T less than or equal to T-g + 6 K. Our analysis also allows on e to detect fluctuations in terms of the resulting apparent homogeneity wit hin the long time tail of the decay. Even at times significantly exceeding the average structural relaxation lime, no sign of a transition towards pur ely exponential or otherwise homogeneous behavior could be observed. This i mplies that even at t approximate to 50[tau](KWW) the individual time const ants remain correlated to their initial values at t = 0.