Comparison between single-longitudinal-mode and two-longitudinal-mode pumping cavity OPSMMWL

Experimentally, a longitudinal mode selected TEA-CO₂ laser was used to be a pumping source and the CO₂-9R(16) line was used to pump a mini-NH₃ cavity optically pumped sub-millimeter wave laser (OPSMMWL), the NH₃ 90.4um SMMW line was obtained by single-longitudinal-mode or two-longitudinal-mode pumping, and experimental comparison of output power and operating gas pressure between single and two-longitudinal-mode OPSMMWL were studied. It was found that the two-longitudinal-mode OPSMMWL could get higher output power and broader spectrum, existed a lower operating gas pressure and wider range of operating gas pressure.