Patent attributes
A method is described to improve and produce purer Cr4+-doped laser materials and lasers with reduced co-incorporation of chromium in any other valence states, such as Cr3+, Cr2+, Cr5+, and Cr6+. The method includes: 1) certain crystals of olivine structure with large cation (Ca) in octahedral sites such as Cr4+:Ca2GeO4, Cr4+:Ca2SiO4, Cr4+:Ca2GexSi1-xO4 (where 0<x<1), and/or 2) high-temperature solution growth techniques that enable the growth of the crystals below the temperature of polymorphic transitions by using low melting point solvent based on oxide, fluoride and/or chloride compounds. Purer Cr4+-doped laser materials are characterized by a relatively high concentration of Cr4+-lasing ion in crystalline host that makes these materials suitable for compact high power (thin disk/wedge) NIR laser applications.
