Compact all-PM fiber gain-managed nonlinear amplification system based on a stretched-pulse oscillator

The high-performance gain-managed nonlinear amplification (GMNA) system benefits from the dynamic interaction between seeding pulses and the evolving gain spectrum, making it ideal for high-power, sub-50-fs fiber laser systems. In this work, we demonstrate a compact all-polarization-maintaining fiber GMNA system based on a stretched-pulse oscillator (SPO). The SPO directly generates high-energy, chirp-optimized pulses for subsequent GMNA, eliminating the need for additional pre-compressors and preamplifiers. By jointly optimizing both the seeding and amplification stages, this monolithic SPO-GMNA laser system enables efficient energy extraction and spectral broadening exceeding 100 nm, delivering 106.8-nJ and 31.8-fs pulses. This robust, high-peak-power femtosecond fiber laser holds significant potential for applications in biomedicine and advanced manufacturing.