
Crystals doped with trivalent ytterbium (Yb³⁺) have demonstrated significant potential for application in compact, efficient, diode-pumped laser systems.[1-4] The Yb³⁺ ion has only two manifolds, the ground ²F₇⸝₂ and the excited ²F₅⸝₂ which are separated by approximately 10,000 cm⁻¹. As a result, Yb³⁺ doped materials have spectroscopic and laser properties that are advantageous for high energy 1 μm laser systems. In particular, Yb³⁺ doped materials should not suffer from concentration quenching, upconversion, or excited state absorption. The Yb³⁺ion also has a long energy storage lifetime (typically three to four times that of Nd³⁺ in the same host) and a very small quantum defect which reduces heat generation during lasing.
