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 photonic-crystal fiber provides dispersion compensation in a soliton fiber laser. The anomalous dispersion provided by the photonic-crystal fiber permits construction of a femtosecond fiber laser at 1 ?m wavelength without prisms or diffraction gratings. The laser produces ˜100-fs pulses with 1 nJ energy, and is a major step toward environmentally-stable all-fiber devices at 1 ?m.

Abstract: A photonic-crystal fiber provides dispersion compensation in a soliton fiber laser. The anomalous dispersion provided by the photonic-crystal fiber permits construction of a femtosecond fiber laser at 1 &mgr;m wavelength without prisms or diffraction gratings. The laser produces ˜100-fs pulses with 1 nJ energy, and is a major step toward environmentally-stable all-fiber devices at 1 &mgr;m.

Abstract: A Kerr-lens mode-locked Cr:fosterite laser 15 operated with negative nonlinear phase shift. The nonlinear phase shift is induced by the cascade x(2) x(2) process in a lithium triborate crystal. Employing the cascade process at large phase mismatch produces a nearly linear frequency chirp. Transform-limited pulses as short as 60 fs are generated with positive cavity dispersion.