Generation of 35 fs, 20 μJ, GHz pulse burst by hybrid fiber amplification technique
J. Ma, Huanhuan Liu, Y. K. Chen, Nan Zhang, Perry Ping Shum
Abstract
We have proposed and demonstrated the generation of a high-energy, ultrashort pulse duration, GHz pulse burst polarization-maintaining fiber amplification system that utilizes both chirped-pulse amplification and self-similar amplification techniques. Such hybrid fiber amplification system produces 22 μJ-energy bursts of 200 pulses with a 1.02-GHz intra-burst pulse repetition rate and a 1-MHz inter-burst repetition rate. The center wavelength of the amplified compressed pulse is 1065 nm, with a 3 dB spectral bandwidth of 65 nm. The pulse duration of optimal compression is ∼35 fs, which represents the shortest pulse duration reported to date for any multi-microjoule class amplification system with a repetition rate at the GHz level. At the same time, only common double-cladding Yb 3+ -doped fiber is used as the gain fiber, without any large-mode-area Yb 3+ -doped photonic crystal fiber, makes the system compact and reliable by the simple fusion operation.