Diode-pumped Tm:CALGO lasers operating on the <sup>3</sup>H<sub>4</sub> → <sup>3</sup>H<sub>5</sub> transition
The performance of the diode-pumped Tm:CALGO laser operating on the <sup>3</sup>H<sub>4</sub> → <sup>3</sup>H<sub>5</sub> Tm<sup>3+</sup> transition was studied in detail by employing the crystals with different Tm<sup>3+</sup> doping levels in the range of 1.5 at.% to 5 at.%, and Watt-level continuous-wave laser operation was first realized. Under the wing-pumping scheme, the maximum laser output power reached 1.48 W with a broad free-running laser spectrum spanning across ~64 nm (2284-2348 nm). The two key energy-transfer processes among Tm<sup>3+</sup> ions governing the efficiency of 2.3-µm Tm lasers, <i>i.e.,</i> cross-relaxation and energy-transfer upconversion, are quantified for Tm:CALGO. Unprecedented long-wavelength emission up to 2.55 µm is also observed from this laser, representing the first evidence of a phonon-terminated (vibronic) lasing associated with the <sup>3</sup>H<sub>4</sub> → <sup>3</sup>H<sub>5</sub> Tm<sup>3+</sup> transition. This work demonstrated the potential of Tm:CALGO crystal for femtosecond pulse generation at 2.3-2.5 µm.
Authors
- Hao Yuan (ORCID: https://orcid.org/0000-0002-7072-9513)
- Zhongben Pan (ORCID: https://orcid.org/0000-0002-7965-7069)
- Dechun Li (ORCID: https://orcid.org/0000-0002-7550-6351)
- Hongwei Chu (ORCID: https://orcid.org/0000-0002-1231-2381)
- Pavel Loiko
- Kirill Eremeev
- Han Pan (ORCID: https://orcid.org/0000-0002-6354-5599)
- Xiaoxu Yu (ORCID: https://orcid.org/0009-0008-9213-1572)
- Alain Braud
- Patrice Camy
Institutions
- China Academy of Engineering Physics (CN)
- Normandie Université (FR)
- Université de Caen Normandie (FR)
Publication Details
- Journal
- Optics Express
- Published
- 2025-03-17
- DOI
- https://doi.org/10.1364/oe.555244
- Citations
- 4
- Primary Topic
- Laser Design and Applications
- Type
- article
- Field-Weighted Citation Impact
- 2.92