A comparative study of D2O oscillators emitting at 385 µm

The generation of single-mode pulses of far-infrared (FIR) radiation of duration up to 700 ns at 385 μm has been achieved using a confocal unstable resonator with D
2
O as an active medium. Future volumetric scaling to the power levels necessary for measuring ion temperature in tokamak plasmas by Thomson scattering appears encouraging. A comparison between the performance of the unstable resonator and two hemispherical resonators is reported.