Self-organizing laser induced Au nanocrystall formation in conditions of surface plasmon resonance

Abstract

The researches of the possibility of Au nanoparticles formation in conditions of surface plasmon resonance (SPR) at irradiation of the Au film / glass structure by YAG:Nd+3-laser nanosecond pulses of the p-polarization (tp = 10 ns) by fundamental (λ = 1.064 nm) and second harmonics (λ = 0.532 nm) are submitted. The morphology of an Au film surface before and after laser action, Au fragments sizes and their surface distribution were investigated by the atom force microscopy (AFM). The effect of Au nanoparticles formation was observed only at the second harmonic irradiation (λ= 0.532 μm) in SPR conditions in the Kretschmann configuration. The considerable difference between the average Au nanoparticles sizes δ created at the SPR conditions, R = Rmin, δ ~ 80 nm that was obtained in the case out of SPR R≠Rmin δ ~ 1350 nm is established. Threshold energy density of micro-ablation Pthn is determined, that one in the case of SPR Pthn ≈ 5.5 J•cm-2 was essentially lower than in the SPR absence, Pthn ≈ 8 J cm-2. The histogram obtained on the AFM data has shown a high degree of the height sizes homogeneity of Au nanoparticles. Under the AFM data a conclusion about the determining contribution of the plasmon - polariton subsystem in formation process of Au nanoparticles in SPR conditions at high levels of laser irradiation was made.