Time-resolved tunable diode laser absorption spectroscopy of pulsed plasma

Area of Science:

• Plasma Physics
• Spectroscopy
• Materials Science

Background:

• Technological plasma systems require precise diagnostics for process optimization.
• Existing spectroscopic methods may lack the temporal resolution to capture transient plasma phenomena.

Purpose of the Study:

• To develop and validate a time-resolved tunable diode laser absorption spectroscopy (LAS) method for analyzing transient plasma dynamics.
• To investigate the temporal evolution of particle density and temperature in technological plasmas.

Main Methods:

• Development of a novel electronic module for time-resolved LAS.
• Utilizing transistor-transistor logic signals for precise laser wavelength tuning and detector signal sampling.
• Application of the developed method to a high-power impulse magnetron sputtering system.

Main Results:

• Demonstrated capability to measure temporal evolution of argon metastable density (Ar*) in plasma ON and afterglow phases.
• Observed a distinct double-peak structure in Ar* density.
• Identified a second peak in Ar* density approximately 1 ms after the plasma pulse termination.

Conclusions:

• The developed time-resolved LAS method and electronic module effectively capture transient plasma behavior.
• The study provides insights into the temporal dynamics of argon metastable species in pulsed plasmas.
• This technique is valuable for diagnostics and understanding of pulsed plasma processes.