High-efficiency infrared xenon laser excited by a UV preionized discharge

We report an efficient high-power laser action in Ar-Xe mixtures at 1.4 atm, without an e-beam, using a simple UV preionized discharge. A "wall-plug" efficiency of 1.5 percent is obtained with an output energy of 48 mJ, and 70 percent of this energy is delivered on the 1.73 μm line. We describe the experimental optimization of the laser efficiency by varying the partial and total pressures of the gas mixtures, the deposited energy density, and the intensity of the UV preionization. The best performances are obtained for a relatively low energy density (about 10 J/l). This result was expected, due to the very strong ionization rate constant of the xenon excited states. We have also achieved interesting results in Kr-Xe, He-Xe, He-Kr, and He-Ar mixtures.