Optimization of femtosecond laser processing in liquids

Abstract

In this paper we analyze femtosecond laser processing of metals in liquids searching for optimal conditions for predictable ablation. Incident laser pulses are stretched or compressed, self-focused and scattered on bubbles and on surface waves in the liquid environment. Influence of these effects on the laser intensity distribution on the target surface is discussed and optimal processing parameters are suggested.

Femtosecond Laser Micromachining of Soda–Lime Glass in Ambient Air and under Various Aqueous Solutions

“…To our knowledge, no studies were performed on femtosecond laser micromachining of soda–lime glass under KOH or NaCl aqueous solutions. Other interesting results were presented on the microfabrication in organic solutions, e.g., methanol, acetone, ethanol and toluene [29,30]. Alcohol-assisted femtosecond photoetching of silicon carbide was shown to be beneficial to decreasing the redeposition of debris and increasing the ablation depth [31].…”

Dynamics of laser-induced cavitation bubble during expansion over sharp-edge geometry submerged in liquid – an inside view by diffuse illumination

“…Optical observation of cavitation bubbles is important for studying acoustic [21] , [54] , hydrodynamic [55] , [56] and laser-induced cavitation [14] , [18] , [40] , [43] , [57] , [58] , as well as to develop different applications including nanoparticle production [8] , [9] , [28] , [30] , underwater breakdown spectroscopy [59] , enhanced heat transfer with nucleate boiling [60] , refrigeration [61] , [62] , microfluidics [63] and laser biomedical procedures [64] . Understanding the influence of illumination on their perception and interpretation can sometimes prove difficult, since it involves refraction and multiple reflection of light at the interface of media with different optical densities.…”

Overcoming the barrier of nanoparticle production by femtosecond laser ablation in liquids using simultaneous spatial and temporal focusing

“…The generation of NPs with PLAL requires continuous working on its challenges, such as the fabrication of NPs with specific size and shape, the reduction of the polydispersity, and the increase of the productivity, among others. Despite some physical, chemical, and technical problems that are still unsolved, several strategies have been presented to take aim at these issues, including post-irradiation of colloids [13,14], different liquid handling configuration [15,16], optimization of the focusing conditions and liquid levels [17,18], selection of the appropriate liquid or stabilizer agent [19,20], and the optimization of the laser parameters [21]. In this sense, to explore in PLAL the wide range of opportunities that bring the unique properties of femtosecond lasers is an appealing hot topic of research not only due to the aim to increase nanoparticle production but also to generate structural modifications and new material phases only achievable with ultrafast and ultraintense pulsed radiation [22][23][24][25][26][27].…”