Phase Transformations in Ultra-fast Laser Processing

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

PHASE TRANSFORMATIONS IN ULTRA-FAST LASER PROCESSING Abstract The main objective of the research is to examine the mechanisms of ultra-fast laser processing of materials. Investigations of the energy transfer, melting, desorption and ablation upon femtosecond laser irradiation will be carried out. Experiments will be conducted to study the femtosecond laser processing of materials including composites, thin films, micro- and nano-structures. Ultra-fast imaging, time-resolved pump-probe reflection, transmission, absorption, scattering, deflection and interferometry measurements will be applied to probe the laser interaction with the irradiated material. The energy distributions of the released particles will be captured by time-of-flight mass spectrometry and spectroscopic analysis of the femtosecond laser-induced plasma. The laser interaction with the target materials will be modeled theoretically and computationally. Ultra-short pulsed laser radiation will be utilized for precision machining, surface engineering, processing and synthesis of advanced materials and nanoparticles. Understanding the associated phase transformations is the central research issue in this work. These extremely rapid phenomena will be interrogated by on-line optical diagnostics and analyzed theoretically.