title: In-band-pumped Ho:KLu(WO4)2 microchip laser with 84% slope efficiency.
abstract: We report on a continuous-wave Ho:KLu(WO4)2 (KLuW) microchip laser with a record slope efficiency of 84%, the highest value among the holmium inband-pumped lasers, delivering 201 mW output power at 2105 nm. The Ho laser operating at room temperature on the (5)I8→(5)I7 transition is in-band-pumped by a diode-pumped Tm:KLuW microchip laser at 1946 nm. Ho:KLuW laser operation at 2061 and 2079 nm is also demonstrated with a maximum slope efficiency of 79%. The microchip laser generates an almost diffraction-limited output beam with a Gaussian profile and a M2<1.1. The laser performance of the Ng-cut Ho:KLuW crystal is very similar for pump light polarizations ‖Nm and Np. The positive thermal lens plays a key role in the laser mode stabilization and proper mode-matching. The latter, together with the low quantum defect under in-band-pumping (∼0.08), is responsible for the extraordinary high slope efficiency.
authors: Pavel
authors: P
authors: Loiko
authors: Josep Maria
authors: JM
authors: Serres
authors: Xavier
authors: X
authors: Mateos
authors: Konstantin
authors: K
authors: Yumashev
authors: Nikolai
authors: N
authors: Kuleshov
authors: Valentin
authors: V
authors: Petrov
authors: Uwe
authors: U
authors: Griebner
authors: Magdalena
authors: M
authors: Aguiló
authors: Francesc
authors: F
authors: Díaz