Abstract
When a laser pulse interacts with metal or semiconducting target, the lattice oscillation, which has phase coherence and nonlinear electron heating, is excited on their surfaces. It is called coherent phonon and has unique properties of decaying in approximately several picoseconds and substance specific frequency. Owing to that, femtosecond laser processing is the local processing with little heat diffusion and little thermal damage to the target due to the ultrafast time scales. We propose a novel femto pulse nano ablation process with oscillation of the coherent phonon. So we use femto pulse train. The pulse train, which is excited by femtosecond pulse, is shaped by using spatial light modulator to control the phase of the passing light. And coherent phonon oscillations are enhanced and decayed due to the controlling the shape of pulse train. It enables to accelerate or decelerate the lattice motion efficiently. Here, we report femto pulse shaping and its time resolving detection system to challenge that method.
