ABSTRACT
More recently Cicerone and Ediger [9] developed an optical deep bleaching technique for selecting a slow subensem ble of fluorescent dye tracers and monitoring its return to equilibrium. T hey concluded that this “structural” relaxation occurred on a tim e scale of about 103 tim es the average rotational correlation tim e in the supercooled liquid ortho-terphenyl (O TP) at T . No indications for such long-lived heterogeneity were found using non-resonant dielectric spectral hole burning experim ents carried out for various other supercooled liquids, including glycerol and propylene carbonate, near T [10].
