Generation of 6-μJ ultrafast pulses from an Er-doped laser system

High-power lasers at 1.55 μm have mostly been constructed in the free-space configuration or the non-polarization-maintaining (PM) fiber structures, which significantly limits the practical deployment in widespread applications. Here, we reported a robust linear-polarized Er-doped laser system, except for the bulky grating pulse compressor. The laser system can deliver high-energy ultrashort pulses at μJ level in a wide range of programmable repetition rates from about 2.1 MHz down to 200 kHz. Specifically, a high pulse energy of 6 μJ, unprecedented in the PM fiber scheme, is achieved at 200 kHz repetition rate, yielding corresponding MW-level peak power. The beam quality is verified by an M²-value of 1.4. The presented laser system features high pulse energy, high peak power, and good beam quality, which constitutes a useful source for diverse applications such as material processing, biomedical imaging, and laser machining.