Optimization of femtosecond laser processing in liquids

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 crystallization of amorphous titanium oxide thin films

In this paper, we demonstrate experimentally that crystalline phases appear in amorphous titanium oxide upon processing with ultrafast laser pulses. Amorphous titanium thin films were produced by plasma-enhanced chemical vapor deposition and exposed to femtosecond laser pulses. Formation of a rutile phase was confirmed by X-ray diffraction, Raman measurements, and electron backscattering diffraction. A range of processing parameters for the crystallization is reported, and possible background mechanisms are discussed. Published by AIP Publishing

Laser-Textured Metal Substrates as Photoanodes for Enhanced PEC Water Splitting Reactions

We demonstrate the effect of femtosecond laser structuring of titanium substrates to increase the absorption, photoconversion, and overall photoelectrochemical water splitting (PEC) performance compared to pristine metal substrates, independent of any additional top coat layers. The influence of ultra short laser pulse patterning on PEC efficiency is investigated toward spectroscopic (UV-Vis), microscopic (SEM), crystallographic (XRD), and compositional (XPS) properties. The beneficial effect of a periodically patterned substrate is attributed to enhanced specific surface area and improved in-plane light trapping when compared to flat surfaces. Photoanodes for water splitting experiments fabricated by titanium and iron oxide films on laser pre-patterned Ti substrates are also found to show enhanced PEC efficiency (0.057 mA cm(-2)) when compared to unpatterened substrates (0.028 mA cm(-2)). The lower absolute PEC efficiencies are due to extreme thin films