Multi-kilowatt, all-fiber integrated chirped-pulse amplification system yielding 40x pulse compression using air-core fiber and conventional erbium-doped fiber amplifier.

We present a totally fiber integrated chirped-pulse amplification system using air-core photonic bandgap fiber and a conventional erbium-doped fiber amplifier. ~40-ps input pulses, generated in a Mach-Zehnder modulator, were stretched and spectrally broadened in a dispersion-shifted fiber before being amplified and subsequently compressed in 10 m of anomalously-dispersive photonic bandgap fiber to yield ~960 fs pulses. The system gives multi-kilowatt peak powers while the amplifier nonlinearity threshold is as low as ~150 W. Higher peak powers could be obtained by the use of an amplifier with higher nonlinearity threshold.