Ultra-short pulsed laser irradiation

STRUCTURING OF METAL SURFACES BY ULTRA-SHORT PULSED LASER IRRADIATION... 

For ultra-short pulsed laser irradiation of metals, with pulse duration smaller than 1 ps, two different ablation regimes, termed gentle and strong ablation, are observed (Nolte et al., 1997). At laser fluences (laser pulse energy per unit area) just above the ablation threshold, the average ablation rate is determined by the optical penetration depth (for example, 13 nm for copper) of laser radiation in metal. The average ablation rate is low. The processed area is relatively smooth with nanometer-sized... 

Table 3 Quantitative Characterization of Superhydrophobic Metal Surfaces Structured by Ultra-Short Pulsed Laser Irradiation Structure...

The results of the quantitative characterization of superhydrophobic metal surfaces structured by ultra-short pulsed laser irradiation are summarized in Table 3. The water contact angles measured prior to the laser irradiation were 65°—85° on copper, titanium, iron, and aluminum... 

Data have been obtained on samples irradiated with ultra-short laser pulses at the laser fluence of 5.16 J/cm and stored under normal ambient conditions for approximately 1 month. 

The ultra violet laser-pulse having such a short pulsewidth Tw as Ins and such a short wavelength as 337.1nm irradiates the silicon surface to excite excess carriers as shown in the bottom left figure of Fig. l.The generated carriers are confined within the subsurface since extremely short penetration depth of 200A. An amplitude (or intensity) of the photoconductivity... 

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