Spectroscopy and efficient laser operation around 2.8 μm of Er:(Lu,Sc)2O3 sesquioxide ceramics

A transparent mixed 7 at.% Er:(Lu,Sc)(2)O-3 sesquioxide ceramic was fabricated by hot isostatic pressing of commercial sesquioxide powders at 1750 degrees C/200 MPa in argon atmosphere. It exhibited a cubic bixbyite-type structure (a = 10.198 angstrom), a mean grain size of 5.7 um and high low-signal transmission of 79.1 % in the near- IR. The spectroscopic properties of Er3+ ions were studied. For the I-4(11/2) -> I-4(13/2) transition, the stimulated-emission cross-section sigma(SE) is 1.30 x 10(-20) cm(2) at 2719 nm, the corresponding luminescence branching ratio B (JJ') is 19.9 % and the radiative lifetime of the I-4(11/2) state is 4.80 ms, as determined using a Judd-Ofelt theory accounting for intermediate configuration interaction. The crystal-field splitting of Er3+ multiplets was studied at 12 K. The ceramic exhibits a significant inhomogeneous broadening of spectral bands. An Er:(Lu,Sc)(2)O-3 ceramic laser generated 342 mW at 2.71 and 2.85 mu m with a high slope efficiency of 41.7 % (exceeding the Stokes limit) and a laser threshold of 125 mW.

Automated summary

A transparent mixed 7 at.% Er:(Lu,Sc)(2)O-3 sesquioxide ceramic was fabricated by hot isostatic pressing of commercial sesquioxide powders at 1750 degrees C/200 MPa in argon atmosphere. It exhibited excellent optical properties with high signal transmission and high slope efficiency. The study of crystal-field splitting of Er3+ multiplets revealed the significant inhomogeneous broadening of spectral bands in the ceramic material.