Laser-matter interaction by dual-wavelength double-pulse irradiation

Relevance: Laser material processing is widely researched in science, technology, and medicine. These studies are very relevant to the search for efficient usage of laser energy for industrial applications. The use of two-wavelength combined irradiation in a laser machining enables the efficiency of the whole process to be improved. This is achieved by initially absorbing the ultra-violet radiation of first pulse when exposed to the sample. Subsequently, an increase in the absorbance of the sample is achieved over a short period of time, thus allowing a greater absorption of infra-red radiation of second pulse that reached the sample. This allows you to absorb majority of laser energy efficiently. Thus, dual-wavelength double-pulse irradiation is relevant to optimizing the laser processing, and contribute to the science of important technological laser applications.
Scientific novelty: Recently, research works emerged in the scientific literature that perform tests using a double or even triple laser pulse sequences for laser processing. The same wavelengths are commonly used for such tests. However, only few scientific groups use two-wavelength combined irradiation. It is a completely new and very little researched area of science and technology that still has a lot of unknowns.
Prospects: The aim of the proposed PhD studies is to study the laser processing (ablation, cutting, surface, and volumetric fracture formation) of various materials (metal, semiconductors, dielectrics, and ceramics) by using two-color double pulse radiation. This is a very promising area of science and technology, since understanding the key mechanisms of two-wavelength dual-pulse laser processing will optimize the process and maximize the use of laser energy. This will result in a number of accelerated laser processing rates and improved quality that will reduce cost of laser technology and applications.
Available equipment: The Department of Laser Technology (LTS), FTMC has a unique laser machining system that can be used to process materials by irradiation with combined irradiation: dual-wavelength (1064 nm and 355 nm) double-pulse pairs with controlled time delay between pulses. FTMC LTS has various equipment for characterizing samples and structures: optical microscopes; scanning electron microscope with EDS / WDS additives for chemical analysis; stylus profiler; atomic force microscope; spectrophotometers. FTMC LTS has a COMSOL Multiphysics software package for numerical modeling and simulation of physical processes.
For more information, please contact the theme supervisor M. Gedvilas.