Millijoule, high-peak power, narrow-linewidth, sub-hundred nanosecond pulsed fibre Master-Oscillator Power-Amplifier at 1.55 μm

Abstract

In the first part of this article we review the challenges associated with erbium–ytterbium doped fibre amplifiers and the design considerations to scale-up the output power and energy using cladding-pumped large-core fibre amplifiers in master-oscillator power-amplifier (MOPA) configuration. Previous results are also given to illustrate this rather successful approach. The second part consists of our latest experimental results with improvements in terms of linewidth and peak power using shorter pulses. Sub-hundred nanosecond pulses with millijoule energy and narrow linewidth were obtained using cascaded fibre amplifiers with large-core fibres. The energy level obtained with such short pulse duration and narrow spectral linewidth is the highest ever reported. System limitations and potential routes for further improvement are also discussed.