Optically pumped microplasma rare gas laser.

Area of Science:

• Atomic Physics
• Laser Science
• Plasma Physics

Background:

• Optically pumped alkali lasers rely on three-state systems.
• Rare-gas metastable lasers offer a chemically inert alternative.
• Efficient generation of metastable atoms is crucial for CW operation.

Purpose of the Study:

• To demonstrate CW optical gain and laser oscillation in a rare-gas metastable system.
• To investigate the generation of metastable argon atoms using a micro-discharge.
• To analyze the collisional energy transfer pathways within the argon metastable manifold.

Main Methods:

• Utilized a linear micro-discharge array for generating metastable Ar(4s, 1s(5)) atoms.
• Operated gas mixtures at near atmospheric pressure under continuous-wave (CW) electric discharge.
• Observed optical excitation at 811.5 nm and laser oscillation at 912.3 nm.
• Employed a steady-state kinetics model to analyze collisional processes.

Main Results:

• Achieved CW optical gain and laser oscillation at 912.3 nm.
• Successfully generated metastable Ar(4s, 1s(5)) atoms at atmospheric pressure.
• Observed efficient 1s(5) → 2p(9) excitation and subsequent 2p(10) ↔ 1s(5) laser transition.
• Kinetics model confirmed efficient collisional coupling within the Ar(4s) manifold.

Conclusions:

• Demonstrated the feasibility of CW optically pumped rare-gas metastable lasers.
• The micro-discharge array is effective for generating necessary metastable species.
• Collisional energy transfer plays a key role in the observed laser oscillation.