Actively pulse-shaped linearly polarized 200 W photonic crystal fiber MOPA at 2048 nm with 2 mJ pulse energy

A pulsed high-power fiber master oscillator power amplifier (MOPA) based on a Tm3+-doped photonic crystal fiber (PCF) with a core diameter of 50 μm is reported. Active pulse shaping allows the generation of close to rectangular-shaped pulses with pulse energies of 2.07 mJ, pulse durations of 49 ns, and peak powers of 52 kW at a pulse repetition rate (PRR) of 100 kHz leading to an average output power of 207 W. The linearly polarized output signal has a narrow 10-dB linewidth of 390 pm at a central emission wavelength of 2048 nm and a nearly diffraction-limited beam quality (M2 < 1.3).