AUTHOR=Chen Hongshan , Yan Lisong , Liu Heyan , Hao Jingjie , Yang Tingting , Liu Hongyu , Zhang Jin , Li Quanming , Wang Hailin , Zhu Guangzhi , Zhu Xiao , Xuan Hongwen , Wang Qing , Zhang Jinwei TITLE=High-efficiency 100-W Kerr-lens mode-locked Yb:YAG thin-disk oscillator JOURNAL=Frontiers in Physics VOLUME=11 YEAR=2023 URL=https://www.frontiersin.org/journals/physics/articles/10.3389/fphy.2023.1191010 DOI=10.3389/fphy.2023.1191010 ISSN=2296-424X ABSTRACT=

We demonstrate a Kerr-lens mode-locked femtosecond Yb:YAG thin-disk oscillator and investigate the approach to increase the optical-to-optical efficiency based on the scheme of direct multiple passes of the laser beam through the thin-disk medium. With twelve passes through the thin disk, 266-fs pulses were delivered from the oscillator with an average power of 105.6 W at a repetition rate of 20 MHz. The corresponding optical-to-optical efficiency is 31.1%, which is, to the best of our knowledge, the highest efficiency of any mode-locked thin-disk oscillator with pulse duration below 300 fs. This demonstration paves the way to even more efficient mode-locked femtosecond thin-disk oscillators, and provides an excellent laser source for the applications such as non-linear frequency conversion and high-precision industrial processing.