Modeling of a picosecond CO₂ amplifier with electrical and optical pumping

As a long-wavelength laser with strong energy storage capacity and large scale of amplification, the CO₂ laser is considered an effective amplifier in the next-generation picosecond terawatt infrared laser system, but the pulse splitting effect caused by its discrete gain spectrum limits its behavior. In this paper, we have developed a specific model of a CO₂ amplifier, which is optically and electrically pumped at the same time. The model is based on gas discharge that is combined with photon absorption, temperature, and wave equation. The proposed hybrid pumped CO₂ amplifier scheme can increase the gain proportion of the sequence band transition (00⁰2-10⁰1, 00⁰3-10⁰2, etc.) from 12% to nearly 50% of the regular band and broaden the bandwidth of each line by over 15.8% by the overlap of the sequence band and regular band. The relative energy concentration of the first subpulse can be increased by up to 190% when the amplification factor reaches 10³. The study on the model of a picosecond CO₂ amplifier with electrical and optical pumping may contribute to the amplification of an ultrafast mid-infrared pulse to the terawatt or higher region.