Lasing in 15 atm CO₂ cell optically pumped by a Fe:ZnSe laser

Area of Science:

• Optics and Photonics
• Laser Physics
• Gas Lasers

Background:

• Optically pumped gas lasers offer tunable wavelength generation.
• Carbon dioxide (CO2) lasers are widely used, but high-pressure operation presents challenges.
• Efficient amplification of short pulses requires understanding gain dynamics.

Purpose of the Study:

• To investigate 10 µm lasing in a compact, high-pressure CO2-He gas cell.
• To determine optimal pumping conditions for CO2 lasing.
• To evaluate the potential for high-pressure CO2 lasers in amplifying picosecond pulses.

Main Methods:

• Optical pumping of a CO2-He cell using a tunable Fe:ZnSe laser around 4.3 µm.
• Systematic variation of pump wavelength, CO2 partial pressure, and total cell pressure.
• Measurement of lasing output and gain lifetime.

Main Results:

• Achieved 10 µm lasing with optimal pump wavelength at ~4.4 µm and CO2 partial pressure of 0.75 atm.
• Reached an optical-to-optical conversion efficiency of ~10% at 7 atm total pressure without cavity optimization.
• Measured a gain lifetime of ~1 µs at pressures above 10 atm.

Conclusions:

• High-pressure optically pumped CO2 is feasible for efficient 10 µm lasing.
• The observed gain lifetime indicates potential for amplifying picosecond pulses.
• Further optimization could enhance conversion efficiency for practical applications.