High Power Diode-Seeded Fiber Amplifiers at 2 μm—From Architectures to Applications

We review recent advances in the development of high power short- and ultrashort pulsed Thulium-doped fiber amplifier (TDFA) systems seeded by semiconductor laser diodes at wavelengths around 2 μm. The diode-seeding and the master oscillator power amplifier (MOPA) design allow for the construction of extremely versatile laser systems that can operate over wide ranges of peak power, pulse energy and repetition rate in the ultrashort picosecond to the long nanosecond pulsed regimes. We present a record peak power of 130 kW and pulse energy of 5 μJ in picosecond mode, while demonstrating user-defined pulse-shaping capabilities at millijoule pulse energy levels in the nanosecond regime from essentially the same amplifier system. The system architecture as well as important design and power scaling considerations are discussed in detail. Additionally, we highlight recent results in the application of these MOPA systems and their high performance TDFA stages in such diverse application areas as next generation telecommunication networks, mid-infrared supercontinuum generation and mid-infrared gas detection in hollow-core photonic bandgap fibers.