All-fibre femtosecond pulse amplification circuit using chirped Bragg gratings

In‐fiber chirped Bragg gratings are used as stretchers and compressors for distortionless amplification of femtosecond pulses in chirped pulse amplification system. It is shown that using opposite directions of pulse propagation the effects of higher order dispersion and grating irregularities can be eliminated and the original pulse shape and duration can be recovered. Using these gratings a compact all‐fiber system consisting of a mode‐locked fiber oscillator and an erbium‐doped fiber amplifier was built. 330 fs bandwidth‐limited pulses from a fiber oscillator were stretched to 30 ps, amplified and recompressed back to 408 fs. The maximum energy of the pulses after the amplifier was 6 nJ and was at the threshold of nonlinear effects for a 30 ps stretched pulse. © 1995 American Institute of Physics.