Nd:YLF laser at 1053 nm diode side pumped at 863 nm with a near quantum-defect slope efficiency

• Published in: Optics and laser technology 2022-05, Vol.149, p.107818, Article 107818
• Main Authors: de Almeida Vieira, Tárcio, Maia Prado, Felipe, Ursus Wetter, Niklaus
• Format: Article
• Language: English
• Subjects: Diode pumping; Efficiency; In-band pumping; Laser emission; Lasers; Nd:YLF crystal; Neodymium doping; Neodymium lasers; YLF lasers
• ISSN: 0030-3992; 1879-2545
• DOI: 10.1016/j.optlastec.2021.107818

•This is the first time that the combination of 863 nm diode pumping and 1053 nm emission is presented. More important, it is the first time that a Nd:YLF laser is presented with almost quantum limited efficiency, even when calculated with respect to incident pump power and not absorbed pump power. All this is achieved using side-pumping, which allows for compact and robust set-ups, while employing very thin active crystals that have demonstrated pump power handling capacities in excess of 200 W in CW mode.•We believe that this result should shed new light on the host YLF, which is known for its capacity of generating excellent beam quality thanks to its low thermal lensing, while having been neglected due to lower reported efficiencies so far. Laser emission at the 1053 nm transition of Nd:YLF4 is demonstrated using diode-side-pumping at 863 nm directly into the emitting level. The laser configuration uses one total internal reflection at the pump face and provides the highest slope efficiency reported for the Nd:YLF4 medium, close to the quantum limit. In quasi-continuous mode, the laser operates with diffraction-limited beam quality and 78.2% slope efficiency with 14.4 W of output power. In continuous mode, 75.7% slope efficiency in both single-mode and multimode operation is achieved, with 13.5 W output power.