Spectroscopy of solid-solution transparent sesquioxide laser ceramic Tm:LuYO3

We report on a detailed spectroscopic study of a Tm3+-doped transparent sesquioxide ceramic based on a solid-solution (lutetia - yttria, LuYO3) composition. The ceramic was fabricated using commercial oxide powders by hot isostatic pressing at 1600? for 3 h at 190 MPa argon pressure. The most intense Raman peak in Tm:LuYO3 at 385.4 cm(-1) takes an intermediate position between those for the parent compounds and is notably broadened (linewidth: 12.8 cm(-1)). The transition intensities of Tm3+ ions were calculated using the Judd-Ofelt theory; the intensity parameters are S12 = 2.537, S14 = 1.156 and S16 = 0.939 [1020 cm(2)]. For the 3F4 -> 3H6 transition, the stimulated-emission cross-section amounts to 0.27 x 10-20 cm2 at 2059nm and the reabsorption-free luminescence lifetime is 3.47 ms (the 3F4 radiative lifetime is 3.85 +/- 0.1 ms). The Tm3+ ions in the ceramic exhibit long-wave multiphonon-assisted emission extending up to at least 2.35 mu m; a phonon sideband at 2.23 mu m is observed and explained by coupling between electronic transitions and the dominant Raman mode of the sesquioxides. Low temperature (12 K) spectroscopy reveals a significant inhomogeneous spectral broadening confirming formation of a substitutional solid-solution. The mixed ceramic is promising for ultrashort pulse generation at > 2 mu m.(c) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

A detailed spectroscopic study of a Tm3+-doped transparent sesquioxide ceramic was conducted, revealing its potential for generating ultrashort pulses.