High power near-infrared radiation (1–3 μm) can be generated with electro-ionization lasers using rare gases at multi-atmosphere pressure. The best performance is obtained in a so-called e-beam sustained discharge where the e-beam is used to ionize the medium and to maintain the stability of the discharge. An intrinsic efficiency of 8% is feasible. The output power saturates with current due to electron collision mixing. A maximum of 8kW/cm3 has been observed.