Single-frequency continuous-wave diode-pumped Pr³⁺:BaY ₂F₈ orange laser

The optical transition (³H₄¹D₂) of trivalent praseodymium embedded in crystalline matrices is a promising candidate for the realization of optically controlled quantum memories. This application requires a specific laser source emitting at 606 nm whose short-term linewidth is smaller than the linewidth of the considered ion, i.e., in the kHz range. Currently, this can only be addressed with a highly frequency stabilized dye laser [1]. In order to develop a simpler all-solid-state laser source suitable for coherent processing of Pr³⁺, we have explored Pr ³⁺-doped fluoride materials which are well-known to offer a large range of available laser transitions in the visible spectrum ranging from blue to red [2] including an orange one around 600 nm, the pumping transitions lying in the blue between 445 and 480 nm. The recent developments of high power blue laser diodes emitting around 445 nm enable now the pumping of Pr-doped lasers in a compact setup. We present, here, the results we obtained with the diode pumping of a Pr³⁺:BaY₂F₈ (Pr:BYF) crystal which emits at 607 nm.