There are several military applications that require high-power lasers that can propagate for large distances through the atmosphere. Missile defense systems are perhaps the best known ”directed energy” examples. As the beam must arrive at the target with sufficient localization to deliver a high flux to a small area, these applications demand very high beam quality. Due to the stringent co-requirements for power and beam quality, gas-phase chemical lasers were the first choice in directed energy development.1 Gas-phase lasers can achieve continuous operation at magawatt (MW) powers, with remarkably high beam quality. A primary advantage of these devices is that heat dissipation is readily handled using gas flow, so that thermal and refractive index gradients within the medium can be minimized. However, from the perspective of deployment, chemical lasers present significant technical and logistical problems, since their reagents are both hazardous and rapidly consumed during operation. Solid-state devices, such as semiconductor and fiber lasers, are efficient, compact and relatively easy to deploy. The downside for solid-state materials is that it is difficult to meet the power and beam quality requirements. The construction of a single-element MW class solid-state laser poses technical challenges that are beyond the reach of current technology. An alternative approach is to combine the outputs from an array of solid-state lasers into a single beam. Attainment of the required beam quality requires coherent beam combination, so phase control of multiple lasers sources becomes the key issue. Options include both active and passive phase control methods, but the former presents significant complications. For passive methods, the most attractive scheme is to use optical pumping of a gas, thereby merging the best characteristics of gas-phase and solidstate lasers. At present, the development of hybrid solid-state/gas-phase Figure 1. Three level laser scheme for an optically pumped atomic gas.