Andrea Cavalleri

Abstract:

To deal with the weakness of traditional delay test techniques, based on the path delay fault model, a new delay test approach including a new delay test output observation method and an adaptive path selection method is proposed in this work. The basic idea of the approach is to measure the signal transition time for each delay test, and more paths are selected for a second stage test (if necessary) to ensure the timing behavior of the circuit under test. Experimental results obtained by computer simulation demonstrate that a more thorough test is really a need if many significantly late signal transitions are observed.

Abstract:

The dynamics of fs-laser ablation of graphite has been investigated experimentally and theoretically. Molecular dynamics caculations, incorporating changes of the interatomic potentials due to electronic excitation, support the experimental observation of two different ablation mechanisms.

Abstract:

Using time-resolved x-ray diffraction the ultafast strain dynamics in fs-laserexcited Ge/Si-heterostructures has been studied. A fluence dependent, anharmonic damping of the impulsively generated acoustic phonons and vibrational transport across the buried Ge/Si-interface are observed.

Abstract:

Using ultrafast X-ray, line radiation generated with a 20-fs multi-terawatt laser system, femtosecond induced lattice dynamics was observed in bulk semiconductors with milliangstrom spatial and picosecond resolution via time resolved X-ray diffraction. Coherent phonon generation and propagation, ultrafast melting of thin films and buried interface lattice coupling were observed.