Tunable infrared solid-state laser materials based on Cr/3+/ in low ligand fields

The discovery of the alexandrite laser based on transitions occurring in Cr(3+) has proved that the optically pumped solid-state laser still holds the key to major technological advances. The present investigation has the objective to show that the application of some broad and loosely stated principles can lead to the discovery of many new materials which hold the promise of more efficient tunable solid-state lasers. The low field crystalline materials discussed include chromium substituted ordered perovskite (elpasolite) fluorides of the composition K2NaSc(1-x)Cr(x)F6 and the aluminum metaphosphate Al(1-x)Cr(x)(PO3)3. The former is a member of a larger series of compounds K2MBF6 where M is Na(+) or Li(+) and B can be one of several trivalent diluent ions of appropriate size and can include Al(3+), Ga(3+), In(3+), Sc(3+), and Y(3+). A survey of luminescent properties of Cr doped materials is presented. Most of them can be considered as potential laser materials.