Chirped-pulse amplification of an erbium-doped fiber laser at 1.6 µm

We have recently investigated the chirped-pulse amplification (CPA) of an erbium-doped femtosecond fiber laser at 1.6 mum, which constitutes one of the most straightforward and efficient ways to produce energetic short pulses in this band. Recent studies demonstrated the potential of erbium-doped fiber based systems to achieve sub-picosecond pulses with tens of muJ at 1.55 mum. Yet, transposing those systems to 1.6 mum is very challenging since the erbium-doped fiber small signal gain is about 5 times higher at 1.55 mum than at 1.6 mum. High gain at 1.55 mum allows the use of short fibers, leading to low nonlinear phase accumulation. On the contrary, low gain at 1.6 mum implies the use of much longer fibers, which decreases the maximum peak power achievable. In this work, we demonstrate for the first time to the best of our knowledge, CPA operation at 1.6 mum in erbium-doped fibers.