Route to All-Fiber Mamyshev Spatiotemporal Mode-Locked Laser With High Average Power/Pulse Energy

Spatiotemporal mode-locked (STML) fiber lasers exhibit potential for high-average-power output owing to larger mode field diameter in multimode fibers and great pump tolerance. However, the average power from the most of the reported STML lasers still remains in the order of several hundred milliwatts, or even lower, contrary to the virtues of multimode fibers. In this work, we construct an all-fiber Mamyshev STML laser and experimentally explore the influence of cavity losses on average power. By optimizing spatial mode filtering, regulating intra-cavity nonlinearity and compensating inter-modal group delay differences, spatiotemporal pulses with average power/pulse energy up to 2 W/135 nJ can be obtained with 2.2 ps temporal widths. Our study substantially expands the design possibilities for more powerful all-fiber STML lasers, rendering them much more amenable for practical implementation.