Wavelength-tunable, picosecond fiber master-oscillator power amplifier source based on an erbium-doped large-core fiber

We present a direct amplification of wavelength-tunable picosecond optical pulses operating in the spectral range of 1535–1559 nm using an erbium (Er)-doped large-core fiber (EDLCF) in a master-oscillator power amplifier (MOPA) configuration. The EDLCF has a core of 40 μm in diameter and is dual-end-pumped by a counter-propagating 976-nm diode laser in the cladding-pumping scheme together with a co-propagating 1480-nm laser in the core-pumping scheme. The MOPA system can generate the peak power and pulse energy of 12.6 kW and 107 nJ, respectively, while keeping an excellent pulse shape and spatial beam quality.