Anomalous Energy Transport to Rear Surface of Microdisks at High Laser Irradiances

In C${\mathrm{O}}_2$-laser irradiation of thick microdisk foils, a significant fraction of the absorbed laser energy is found to be coupled to the rear surface. Moreover, $K\alpha$ and fast-ion emission has given, for the first time, direct evidence that the rear surface is subjected to considerable bombardment, by the transport of hot electrons around the target.