Kilowatt-Level Pulsed Fiber Laser Based on Homemade Triple-Cladding Yb-Doped Fiber

A kilowatt level nanosecond pulse fiber laser based on domestically produced 150/370/435 μ m ytterbium doped triple clad fiber was reported. A pulse modulated semiconductor laser was used as the seed light source, and a domestically produced three clad ytterbium doped active fiber was used as the main amplification stage gain fiber. Through a four stage main oscillator power amplifier (MOPA) structure, a kilowatt level average power all fiber pulsed fiber laser was achieved. By optimizing the seed light pulse parameters, signal light intensity, and main amplifier pumping method, the output characteristics of the laser were studied in two different modes: hundreds of nanoseconds pulse width, tens of kilohertz repetition rate, and tens of nanoseconds pulse width, several megahertz repetition rate. The synergistic output of high average power and high single pulse energy was achieved. At a pulse width of 208.19 ns and a repetition rate of 70 kHz, the average output power is 1685 W and the single pulse energy is 24.07 mJ. At a pulse width of 20.98 ns and a repetition rate of 1 MHz, the average output power is 1754 W and the single pulse energy is 1.75 mJ. In both modes, the slope efficiency is higher than 70%.