Experimental and theoretical studies on NIR luminescence of titanate‐germanate glasses doped with Pr <sup>3+</sup> and Tm <sup>3+</sup> ions
Marta Kuwik, Karolina Kowalska, Joanna Pisarska, Wojciech A. Pisarski
Abstract
Abstract Near‐infrared (NIR) luminescence of Pr 3+ and Tm 3+ ions in titanate‐germanate glasses has been studied for laser and fiber amplifier applications. The effect of the molar ratio GeO 2 :TiO 2 (from 5:1 to 1:5) on spectroscopic properties of glass systems was studied by absorption, luminescence measurements, and theoretical calculations using the Judd–Ofelt theory. It was found that independent of the TiO 2 concentration, intense NIR emissions at 1.5 and 1.8 μm were observed for glasses doped with Pr 3+ and Tm 3+ ions, respectively. Moreover, several spectroscopic and NIR laser parameters for Pr 3+ and Tm 3+ ions, such as emission bandwidth, stimulated emission cross‐section, quantum efficiency, gain bandwidth, and figure of merit, were determined. The results were discussed in detail and compared to the different laser glasses. Systematic investigations indicate that Pr 3+ ‐doped system with GeO 2 :TiO 2 = 2:1 and Tm 3+ ‐doped glass with GeO 2 :TiO 2 = 1:2 present profit laser parameters and could be successfully applied to NIR lasers and broadband optical amplifiers.