An efficient, compact pulsed D₂O terahertz super-radiant laser pumped with a fundamental transverse mode transversely excited atmospheric pressure CO₂ laser

An efficient, compact pulsed D₂O terahertz (THz) super-radiant laser pumped by a TEA (transversely excited atmospheric pressure) CO₂ laser is presented. The pulse energy of the THz laser has been discussed as a function of CO₂ laser pump energy, D₂O gas pressure, and pump absorption. A pulse width of about 110 ns and the maximum pulse energy of about 1.3 mJ have been achieved at 385 μm, with pumping by a 378 mJ fundamental transverse mode TEA CO₂ laser, and the photon conversion efficiency of 29% has been achieved. We have also studied the temporal behavior features such as the decay time, the full width at half-maximum, and the pulse broadening of the THz laser pulse compared with the pump pulse and the residual pump pulse at the optimum pressure.