Resonantly-pumped Pr3+-doped eye-safe laser at ∼1.65 µm

This study presents a resonantly-pumped laser operation based on the inter-Stark transitions between the ³F₃ and ³H₄ multiplets of Pr³⁺ ion. In this investigation, resonantly-pumped (at ~1547 nm), low quantum defect, laser action is achieved at 1676.5 nm from a Pr³⁺-doped RbPb₂Cl₅ (RPC), low-phonon single crystal, which has recently been reported to lase at 2.5 mum. Hence, this type of laser holds promise for attaining a more efficient, resonantly-pumped, ultra-low quantum defect, eye-safe laser based on this gain medium. Furthermore, much lower nonradiative losses are expected, due to a very low phonon energy found in the Pr³⁺-doped material.