High Power Femtosecond Yb Mode-Locked Pulse Laser Generation Using Hybrid Nonlinear Polarisation Rotation and FePS3 2D Material

Abstract

Developing high-power ultrashort pulse lasers is important for numerous advanced applications in science and technology, such as laser cutting and micromachining. Previous work in this area has often been limited to achieving low-power outputs, hindering the broader application potential of these lasers. This work demonstrated both high power and ultrashort pulses in ytterbium (Yb) mode-locked lasers by the integration of hybrid nonlinear polarisation rotation (NPR) with iron phosphate trisulfide (FePS₃) two-dimensional (2D) material saturable absorber (SA). The primary objective of this research is to enhance the performance of mode-locked fibre lasers, achieving ultrashort pulse durations and higher output power. A novel ytterbium-doped fibre laser (YDFL) system was designed, merging the advanced NPR technique with FePS₃-SA. The experimental configuration yielded a laser emitting at a central wavelength of 1077 nm, featuring an impressive 3-dB bandwidth of 19.8 nm, and generating pulse durations as brief as 0.14 ps. Operating at a repetition rate of 22.6 MHz, the laser achieved an outstanding signal-to-noise ratio (SNR) exceeding 60 dB. Furthermore, the hybrid mode-locked fibre laser exhibited optical peak and average output powers of 245 kW and 0.67 W, respectively. The successful deployment of this cutting-edge hybrid mode-locking technique opens new opportunities for groundbreaking research and innovation in the field of fibre lasers. This work not only demonstrates a significant leap in laser technology but also sets a new benchmark for future explorations and applications in ultrafast optics and photonics.