Single-beam thermowave analysis of semiconductors

The paper describes a new single-beam thermowave technique based on a two-frequency modulation of the laser beam used for both excitation and detection of the photothermal response in a sample. This technique provides frequency transformation to the low-frequency region and, to a certain degree, phase sensitivity without applying the lock-in detection method. This single-beam technique is proved to yield substantial evidence in the field of laser annealing of semiconductors such as the annealing threshold, the defects generated by the ultrafast solidification and the homogeneity of the laser beam applied for irradiation.