Novel Concepts in High-Energy Femtosecond Fiber Lasers

Fiber lasers offer major practical advantages as sources of ultrashort pulses. The average powers of fiber sources now reach, and exceed, those of solid-state femtosecond lasers. However, the pulse energy is chronically limited by excessive nonlinearity. New concepts such as self-similar pulse evolution in a laser and chirped-pulse fiber oscillators are explained. Finally, a new kind of femtosecond laser, which requires no intracavity anomalous dispersion, can be implemented in fiber. The behavior and performance of all-normal-dispersion ytterbium fiber lasers will be described.