Abstract: A chirped-pulse fiber amplification method and system operates with large nonlinear phase shifts (as large as ˜20? or more). In this regime, the pulse spectrum is modified by strong self-phase modulation and gain shaping. With large-enough nonlinear phase shift, substantial spectral broadening occurs. The amplified spectrum can therefore be much broader than the spectrum that is obtained with small nonlinear phase shifts. The broader spectrum enables the formation of a shorter pulse, and the bandwidth generated in nonlinear chirped-pulse amplification can in fact be exploited to generate shorter pulses. Ultimately, this allows the generation of pulses shorter than the gain-narrowing limit of a fiber amplifier.

Abstract: A short-pulse fiber amplifier system (10) is designed so that nonlinear phase shifts and third-order dispersion are purposely introduced that compensate each other. In particular, the nonlinear phase shift accumulated in the amplifier is compensated by the third-order dispersion of the combination of a fiber stretcher (12) and a grating compressor (16). In the presence of third-order dispersion, an optimal nonlinear phase shift reduces the pulse duration, and enhances the peak power and pulse contrast compared to the pulse produced in linear propagation.

Abstract: A short-pulse fiber amplifier system (10) is designed so that nonlinear phase shifts and third-order dispersion are purposely introduced that compensate each other. In particular, the nonlinear phase shift accumulated in the amplifier is compensated by the third-order dispersion of the combination of a fiber stretcher (12) and a grating compressor (16). In the presence of third-order dispersion, an optimal nonlinear phase shift reduces the pulse duration, and enhances the peak power and pulse contrast compared to the pulse produced in linear propagation.

Abstract: A chirped-pulse fiber amplification method and system operates with large nonlinear phase shifts (as large as ˜20? or more). In this regime, the pulse spectrum is modified by strong self-phase modulation and gain shaping. With large-enough nonlinear phase shift, substantial spectral broadening occurs. The amplified spectrum can therefore be much broader than the spectrum that is obtained with small nonlinear phase shifts. The broader spectrum enables the formation of a shorter pulse, and the bandwidth generated in nonlinear chirped-pulse amplification can in fact be exploited to generate shorter pulses. Ultimately, this allows the generation of pulses shorter than the gain-narrowing limit of a fiber amplifier.