Tunable diode laser absorption spectroscopy of argon metastable atoms in Ar/C2H2 dusty plasmas

The tunable diode laser absorption spectroscopy method was used to measure Ar metastable density in order to study the dust growth process in hydrocarbon-containing plasmas. A simple model was proposed that successfully interprets the experimental results of pristine plasmas. The model is also suitable for explaining the influence of dust particle size on metastable density and for examining the dust growth process. The metastable density responded strictly to the formation of dust particles and their growth in processing plasmas. Using metastable density as an indicator is, therefore, a non-intrusive and effective method for the study of the dust growth process in hydrocarbon-containing plasmas.