Sub-50-fs Kerr-lens mode-locked Yb-doped fluoride laser with 44% optical efficiency

• Published in: Applied optics. Optical technology and biomedical optics Vol. 63; no. 4; p. 912
• Main Authors: Su, Xiancui, Wang, Yiran, Su, Liangbi, Liu, Shande, Zheng, Lihe, Zhang, Bingyuan, He, Jingliang, Zhang, Baitao
• Format: Journal Article
• Language: English
• Published: United States 01.02.2024
• ISSN: 2155-3165
• DOI: 10.1364/AO.509994

Yb-doped fluoride has been demonstrated to be potential crystals for application in efficient ultrafast lasers. However, the trade-off between the shorter pulses with higher efficiencies is a challenge. In this work, using , : crystal, we report on a sub-50-fs Kerr-lens mode-locked oscillator with an optical efficiency up to 44%. Pumped by a 976-nm diffraction-limited fiber laser and using chirped mirrors combined with prism pairs for the dispersion compensation, a pulse as short as 46 fs was obtained with 620-mW output power, corresponding to an optical efficiency more than 40%. Stable Kerr-lens mode-locking with RMS of output power lower than 0.3% and beam quality factors <1.14 were achieved. Moreover, a maximum output power of 780 mW was obtained in continuous-wave operation with 55.3% optical efficiency. To the best of our knowledge, the results in this work represent the shortest pulses generated from Yb-doped fluoride lasers as well as the highest optical efficiencies ever reported in sub-100 fs Yb bulk lasers.