Yellow laser performance of Dy$^{3+}$ in co-doped Dy,Tb:LiLuF$_4$

TL;DR

This paper demonstrates a yellow laser at 578 nm using Dy$^{3+}$ ions in co-doped LiLuF$_4$ crystal pumped by a blue diode, with potential applications in metrology and atomic clocks.

Contribution

It reports the first room-temperature continuous wave yellow laser at 578 nm from Dy$^{3+}$ in co-doped LiLuF$_4$, including growth, spectroscopy, and laser performance.

Findings

Achieved cw laser emission at 578 nm with a hemispherical cavity.

Used energy transfer to quench lower laser level via Tb$^{3+}$ co-doping.

Potential for metrological applications, especially in atomic clocks.

Abstract

We present laser results obtained from a Dy$^{3+}$-Tb$^{3+}$ co-doped LiLuF$_{4}$ crystal, pumped by a blue emitting InGaN laser diode, aiming for the generation of a compact 578 nm source. We exploit the yellow Dy$^{3+}$ transition $^{4}$F$_{9/2}$ $\Longrightarrow$ $^{6}$H$_{13/2}$ to generate yellow laser emission. The lifetime of the lower laser level is quenched via energy transfer to co-doped Tb$^{3+}$ ions in the fluoride crystal. We report the growth technique, spectroscopic study and room temperature continuous wave (cw) laser results in a hemispherical cavity at 574 nm and with a highly reflective output coupler at 578 nm. A yellow laser at 578 nm is very relevant for metrological applications, in particular for pumping of the forbidden $^{1}$S$_{0} \Longrightarrow ^{3}$P$_{0}$ Ytterbium clock transition, which is recommended as a secondary representation of the second in the international system (SI) of units. This paper was published in Optics Letters and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://dx.doi.org/10.1364/OL.39.006628. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.