| Abstract [eng] |
In recent years, the use of femtosecond pulse lasers for material processing has been extensively studied both theoretically and experimentally. The interest in material processing with femtosecond lasers is related to the advantages compared to long-pulse lasers (~ns). Ultra-short (on the order of hundreds of femtoseconds) pulses result in high spatial resolution and reduced thermal damage compared to other types of lasers. Laser radiation is widely used for thin film removal in techniques such as lithography, mask repair, thin film micro structuring, data and information recording, as well as laser film transfer and many other areas. Due to the dominant nonlinear absorption in femtosecond processing, it is challenging to remove layers on the order of tens of nanometers. Polymers have attracted much attention due to their unique physical, chemical, mechanical, thermal, electrical, and optical properties, which contribute to their light weight, low surface energy, corrosion resistance, low friction coefficient, and more. However, due to nonlinear absorption during femtosecond processing, achieving low surface roughness (Ra > 0.4 µm) is not possible. To optimize the laser processing of specific materials, suitable radiation is required. Optical parametric amplification is currently becoming a leading solution for generating high-power, ultra-broadband light. The main advantage of the OPA scheme is its wide spectral range, which is not achievable with other laser technologies. The paper describes experiments on damage formation in dielectric coatings and plastic ablation using femtosecond radiation of unconventional wavelengths (1-3.5 µm). The possibility of removing a thin layer of dielectric coating (< 60 nm) by selecting an appropriate wavelength is presented. The possibilities of plastic ablation using different ablation parameters to achieve lower surface roughness have been reviewed. |
