Near-surface Plasma Formation in Air under Action of Two Laser Pulses at Two Wavelengths on Titanium in the Air

The spectra and structure of the near-surface plasma formation were experimentally investigated with a two-pulse laser effect at wavelengths of 532 and 1064 nm on a titanium target in the air, depending on the time interval between laser pulses and their order. The dependences of the temperature of the laser plasma on the parameters of paired laser pulses were established for laser radiation power densities of q1064 ≤ 3.9·10
⁹
W/cm
²
, and of q0.532 ≤ 2.7·10
⁹
W/cm
²
at wavelengths of 1064 and 532 nm, respectively. It is shown that optimal conditions for recording the erosion plasma spectra are provided with a leading effect on second harmonic radiation with a time interval between laser pulses of 4-5 μs, which is important for increasing the efficiency of the laser emission spectral analysis and laser-plasma processing of materials.