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Jo May 25, 2025

Transversely excited atmospheric pressure (TEA) CO₂ lasers have been widely developed and used due to their high peak power and short pulse width, and research into them is being further intensified. TEA CO₂ lasers have been used in the photochemical fields such as light detection and ranging of atmospheric pollutants (LIDAR) and laser isotope separation. TEA CO₂ lasers have also been used for laser particle acceleration, synthesis of nanoparticles, and rapid large paint stripping required in the aerospace industry.

In order to study the dynamics of TEA CO₂ laser, multi-temperature models such as four-, five- and six-temperature models have been developed and different simulation methods have been introduced. Here, the six-temperature model is accepted as the most suitable model to describe the dynamics of TEA CO₂ laser, taking into account all possible vibrational-rotational transitions of gas mixture. The six-temperature model considers the given gas mixture ratio, total pressure, laser cavity geometry, pumping mechanism and discharge gap geometry, etc. to determine simulation parameters including excitation rate and relaxation time, and to simulate TEA CO₂ laser dynamics.

Although some preceding experimental results have reported that addition of a small amount of hydrogen to the gas mixture of TEA CO₂ laser leads to higher power and efficiency, unfortunately, little has been investigated about the theoretical modeling and dynamics of hydrogen-doped TEA CO₂ laser.

Pak Kwang Il, a researcher at the Faculty of Physical Engineering, has developed an improved six-temperature model, taking into account the effect of hydrogen on the vibrational levels of gas mixture. Through the simulation of the dynamic processes of the hydrogen-doped TEA CO₂ lasers, he determined the optimized gas mixture ratio to increase the output power and the pulse energy.

You can find the details in his paper “Improved six-temperature model and simulation for dynamics of high-power TEA CO₂ lasers considering effect of hydrogen” in “Optics and Laser Technology” (SCI).