Subthreshold two-pulse time-delayed laser ionization of Cu

Pressure Effects in Laser-Induced Plasmas of Trinitrotoluene and Pyrene by Laser-Induced Breakdown Spectroscopy (LIBS)

“…A quadrupled Nd:YAG laser (266 nm, 12 mJ, 5 ns pulse width) was used to irradiate the organic samples in solid phase placed into a stainless steel vacuum chamber as described previously. 14 The laser beam, after passing a high-energy variable attenuator (model M-935-10, Newport) was focused with a quartz plane-convex lens (focal length, 200 mm) 20 mm above the surface of the sample (lens-to-sample distance, 180 mm), and the radiation emitted from the plasma plume was collected through the lateral quartz view port of the chamber by a 7.62 cm (3 in) quartz plane-convex focal lens (150 mm). After being reflected with a ultraviolet-coated mirror placed at 45° to the collection path, the emission from the whole plasma was tightly focused (0.5×) in the extreme of a quartz optical fiber (600 μm in diameter) placed orthogonal to the plume expansion direction and connected to the entrance slit of a 500 mm focal-length imaging spectrograph, equipped with an intensified charge-coupled device as a detector.…”

[INVITED] Control of femtosecond pulsed laser ablation and deposition by temporal pulse shaping

“…These techniques have been applied to improve processes such as laser microfabrication of metals [23][24][25][26][27][28][29], dielectrics [27,30,31], or semiconductors [27,[31][32][33] Laser-Induced Breakdown Spectroscopy (LIBS) [27,[34][35][36][37][38] and PLD [4,15,16]. With the advent of automated pulse-shaping techniques, the phase modulation deriving from spectral filtering of femtosecond laser pulses [39] and the associated effect in the temporal domain allow to design more complex temporal pulse shapes.…”

Experimental variables and matrix effects associated with the onset of ion generation in laser ionization of solid samples

“…2 For a fixed sample, laser type, and excitation/collection conditions, the progressive increment of the laser energy released to the target that leads from simple sample decoloration to phase explosion allows the determination of the energy thresholds required to overcome the different enthalpies for each process. [3][4][5] Each step may be explained by a single dominating process in the simplest case or by several simultaneous competing processes, which makes a microscopic description of the whole process quite difficult. 6 Thus, different techniques are required to determine the different thresholds associated with the laser-matter interaction at the different fluence regimes.…”