Spectroscopic characterization of laser ablated silicon plasma

Abstract

We report plasma parameters of laser ablated silicon plasma using the fundamental (1064 nm) and second harmonics (532 nm) of a Nd : YAG laser. The electron temperature and electron number density are evaluated using the Boltzmann plot method and Stark broadened line profile, respectively. The electron temperature and electron number density are deduced using the same laser irradiance 2–16 GW cm−2 for 1064 nm and 532 nm as 6350–7000 K and (3.42–4.44) × 1016 cm−3 and 6000–6400 K and (4.20–5.72) × 1016 cm−3, respectively. The spatial distribution of plasma parameters shows a decreasing trend of 8200–6300 K and (4.00–3.60) × 1016 cm−3 for 1064 nm and 6400–5500 K and (5.10–4.50) × 1016 cm−3 for 532 nm laser ablation. Furthermore, plasma parameters are also investigated at low pressure from 45 to 550 mbar, yielding the electron temperature as 4580–5535 K and electron number density as (1.51–2.12) × 1016 cm−3. The trend of the above-mentioned results is in good agreement with previous investigations. However, wavelength-dependent studies and the spatial evolution of plasma parameters have been reported for the first time.