Brunzell Martin, Widarsson Max, Laurell Fredrik, Pasiskevicius Valdas
Department of Applied Physics, KTH Royal Institute of Technology, Albanovägen 29, Stockholm, 114 19, Sweden.
Sci Rep. 2025 Jul 1;15(1):20980. doi: 10.1038/s41598-025-07313-x.
In this work, the development of a novel ultra-short laser system is presented, building upon previous research in passive mode-locking using cross-amplitude modulation (XAM). By combining XAM with cascaded second-order nonlinearity mode-locking (CSM) the system produced a stable bright-dark two-color output with picosecond pulses and a repetition rate of 275 MHz with an average output power of 100 mW for an 808 nm pump power of 4 W. The experimental setup involved two Nd: YVO lasers operating at 1064 nm and 1342 nm, where the two cavities were interconnected with a dichroic mirror allowing for a shared section where a periodically poled KTiOPO (PPKTP) was introduced. In the separate sections, the independently diode-pumped laser crystals were placed. The enhanced intra-cavity intensity achieved through XAM enabled effective pulse compression via CSM. The results demonstrate the system's ability to generate near-transform-limited pulses as short as 14 ps, offering potential for applications such as medical imaging and LIDAR.
在这项工作中,基于先前在利用交叉幅度调制(XAM)进行被动锁模方面的研究,提出了一种新型超短激光系统的开发。通过将XAM与级联二阶非线性锁模(CSM)相结合,该系统产生了稳定的亮暗双色输出,具有皮秒脉冲,重复频率为275 MHz,对于4 W的808 nm泵浦功率,平均输出功率为100 mW。实验装置包括两台工作在1064 nm和1342 nm的Nd:YVO激光器,其中两个腔通过一个二向色镜互连,形成一个共享部分,在该部分引入了周期性极化的磷酸钛氧钾(PPKTP)。在单独的部分中,放置了独立的二极管泵浦激光晶体。通过XAM实现的腔内强度增强使得能够通过CSM进行有效的脉冲压缩。结果表明,该系统能够产生短至14 ps的近变换极限脉冲,为医学成像和激光雷达等应用提供了潜力。