Pulsed CH3OH Terahertz Laser Emission Pumped by a TEA CO2 Laser

A simple terahertz (THz) cavity and a TEA CO2 laser for the optically pumped THz emission is studied experimentally. To obtain high peak power of pump laser, pressure ratios of gas mixture in the cavity of the TEA CO2 laser are discussed. When CH3OH are pumped by the 9P(16) and 9P(36) CO2 laser lines, the generation of terahertz radiation with energy as high as 353 µJ and 307 µJ are obtained, respectively. The corresponding photon conversion efficiencies are 0.705% and 0.29%. Meanwhile, higher peak power of pump laser effectively improves the photon conversion efficiency. And the optimum THz laser pressure increases with narrower pulse width of pump laser.

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