Enhanced dual electro-optic comb spectroscopy for rapid metastable helium detection

Area of Science:

• Physics
• Spectroscopy
• Plasma Science

Background:

• Dual-comb spectroscopy is a key technique in precision metrology.
• Electro-optic comb (EO-comb) technology offers wide spectral range and high-speed acquisition.
• Plasma diagnostics require precise and fast measurement techniques.

Purpose of the Study:

• Extend dual electro-optic comb (EO-comb) technology for plasma diagnostics.
• Achieve high-speed, sub-microsecond measurements of plasma properties.
• Analyze various plasma species and their dynamic behavior.

Main Methods:

• Utilized dual EO-comb technology with a large repetition rate difference.
• Measured metastable helium density and temperature at sub-microsecond rates.
• Observed distinct plasma phases: discharge, rise, steady-state, and quenching.

Main Results:

• Demonstrated sub-microsecond density and temperature measurement rates for metastable helium.
• Experimental results closely matched theoretical predictions, confirming accuracy.
• Identified potential for improved density resolution through hardware optimization.

Conclusions:

• Dual EO-comb spectroscopy is effective for high-repetition-rate plasma diagnostics.
• The technique enables simultaneous, high-precision measurements of plasma density, temperature, and velocity.
• Future work with nonlinear fibers can expand accessible atomic transitions for comprehensive plasma analysis.