All-fiber spatiotemporal self-similar laser

Self-similar evolution has garnered significant attention in the field of high-power ultrafast fiber lasers due to its unique characteristics, such as wave-breaking suppression and quasi-linear chirp properties. Here, we demonstrate the spatiotemporal similariton generation in an all-fiber laser system through dual-function spectral-spatial filtering enabled by a commercial single-mode fiber filter. The system delivers similaritons centered at 1066 nm with M²≈2.9 beam quality, achieving 420 mW average power at a 13.21 MHz repetition rate, along with 8.2 ps pulse duration (191 fs after dechirping) and pulse energy exceeding 30 nJ. Furthermore, similariton molecules and similariton quartets with different pulse separations are experimentally discovered. This structurally simple design, combined with high-performance output, provides novel, to our knowledge, perspectives for optimizing high-power pulsed lasers, suggesting new pathways for advancing the field.