Spectroscopy and efficient OPSL-pumped laser operation of Er:BaF<sub>2</sub> crystal at 2.8 µm
We present growth, spectroscopy and efficient laser operation of the cubic fluoride crystal Er:BaF<sub>2</sub> at 2.8 µm. An Er(3.6 at.%):BaF<sub>2</sub> crystal was grown by the vertical Bridgman method. We reveal the thermal conductivities of pure BaF<sub>2</sub> and Er:BaF<sub>2</sub> crystals for different temperatures. The temperature-dependent cryogenic absorption spectra were investigated in the near-infrared range, and we determined the energetic positions of the Stark levels of the upper and lower laser multiplets <sup>4</sup>I<sub>11/2</sub> and <sup>4</sup>I<sub>13/2</sub>, respectively. A strong absorption peak at 971.5 nm and a broad gain bandwidth around 2.7-2.9 µm with a large emission cross section at 2732 nm were found. Under pumping with an optically-pumped semiconductor laser (OPSL) at 971.5 nm, we obtained 0.4 W of output power at a wavelength of 2786 nm with a slope efficiency of 31%. The slope efficiency is the highest in reported for 3 µm lasers based on Er:BaF<sub>2</sub> at present.
Authors
- Jun Tang (ORCID: https://orcid.org/0000-0001-6940-7157)
- Christian Kraenkel
- Sascha Kalusniak (ORCID: https://orcid.org/0000-0001-9920-0704)
- Wentao Hou (ORCID: https://orcid.org/0000-0002-0464-6381)
- Stefan Püschel (ORCID: https://orcid.org/0009-0002-6206-0677)
- Hiroki Tanaka (ORCID: https://orcid.org/0000-0002-6195-3177)
- Jun Xu (ORCID: https://orcid.org/0000-0002-9591-765X)
Institutions
- Tongji University (CN)
- Leibniz Institute for Crystal Growth (DE)
Publication Details
- Journal
- Optics Express
- Published
- 2025-01-29
- DOI
- https://doi.org/10.1364/oe.550678
- Primary Topic
- Solid State Laser Technologies
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Natural Science Foundation of China
- National Key Research and Development Program of China