Achieving ultra-short pulse in mode locked fiber lasers by flattening gain shape

A method for generating a pulse-shaped transform-limited output laser from a laser cavity comprising a laser gain medium, the method comprising:

• forming said laser cavity by employing a positive dispersion fiber segment and a negative dispersion fiber segment for generating a net negative dispersion;
• projecting an input laser from a laser pump into said fiber laser cavity for amplifying and compacting a laser pulse in said gain medium to balance a dispersion induced nonlinearity with a self-phase modulation (SPM) in said fiber laser cavity for generating an output laser with a transform-limited pulse shape;
• flattening a gain over a range of wavelengths by implementing a gain-flattening filter whereby the laser cavity is enabled to amplify a laser with improved pulse shape over the range of the wavelengths.

The method of claim 33 wherein:

• said step of implementing a gain-flattening filter further comprising a step of disposing said gain-flattening filter before said gain medium.