Tunable diode laser diagnostics for atmospheric pressure plasmas

Tunable diode laser diagnostics based on spectrally resolved laser absorption have been developed to probe the excited states 4S3P2,1 (IS5,4 Paschen notation) of atomic argon in an atmospheric pressure plasma produced by an inductively coupled plasma (ICP) torch. The purpose of this research is to explore the use of compact, continuous-wave, semiconductor diode lasers as light sources for laser-based diagnostic techniques in high temperature, atmospheric pressure plasmas. Plasma parameters to be determined include electron number density (ne), population temperature (Tpop), and kinetic temperature (T).