Abstract: A phosphate laser glass in which the optical path length is substantially independent of temperature, or "athermal", particularly under rapid pulsing, and chemically stable, while providing high gain. The base glass composition comprises, in mole percent, 55 to 70% P.sub.2 O.sub.5, 3 to 15% of an alkali metal oxide, preferably Li.sub.2 O plus K.sub.2 O, 20 to 30% BaO and 0.5 to 5% Al.sub.2 O.sub.3. Up to 15% of the BaO may be replaced by CaO, SrO or MgO and part of the Al.sub.2 O.sub.3 may be replaced by Nd.sub.2 O.sub.3. The total Al.sub.2 O.sub.3 plus Nd.sub.2 O.sub.3 is 4 mole percent .+-.1.5%. The laser glass composition also includes a laseable component, preferably Nd.sub.2 O.sub.3 and preferably includes a solarization inhibitor.

Abstract: Laser phosphate glass compositions are provided by combining constituent elements at defined amounts to form compositions which provide a balance of properties to the glass, especially high gain and low n.sub.2.

Abstract: Laser phosphate glass compositions are provided by combining constituent elements at defined amounts to form compositions which provide a balance of properties to the glass, especially high gain and low n.sub.2.