Experimental study on the spectral and spatial characteristics of a high-power He-SrBr2 laser

An active volume scaling in the bore and length of a Sr atom laser excited in a nanosecond pulse longitudinal He-SrBr2 discharge is carried out. The optimal temperature regime is found for laser oscillation on several different Sr atom and ion lines. The optimal discharge conditions for achieving a maximal multiline average output power are also found. At multiline operation a record average output power of 4.25 W is obtained, more than 90% of which is concentrated on the 6.45 μm Sr atom line. The radial distribution of the laser intensity is obtained experimentally to be a high-beam-quality Gaussian profile.