Generation of 8.9 mJ Pulses at 717 nm in a Cavity-Dumped Pr³⁺-Doped Fiber Laser

As the broad applications in biomedical imaging, radar detection, and scientific research, pulse lasers in the deep-red region have gained extreme interest. Herein, we successfully generated the actively Q-switched and cavity-dumped lasers at 717 nm. By utilizing AOM, the pulse laser has a maximum average output power of 836 mW at 200 kHz and a narrow pulse width of 40 ns at 5 kHz, which was the first demonstration in double-cladding Pr:ZBLAN fiber. The pulse energy reaches 128 μJ and the corresponding peak power is 3.6 kW at 5 kHz. In the cavity-dumping operation, the pulse laser has a maximum output power of 1.05 W, and the narrowest pulse width of 126 ns was measured at 5 kHz. The maximum pulse energy of 8.9 mJ and the peak power of 48 kW was achieved at 100 Hz, which is the highest than those of the deep-red lasers previously reported. We believe this work paves the way for narrow-pulse width and high single-pulse energy lasers in other rare-earth-doped fibers.