Seeder for use with a fiber laser for generating an arbitrary shaped pulse, comprising an amplified spontaneous emission (ASE) source, a spectral filter and an arbitrary waveform generator (AWG) modulator, the ASE source for generating a continuous wave (CW) broadband pulse, the spectral filter being coupled with the ASE source for narrowing the CW broadband pulse, and the AWG modulator being coupled with the spectral filter for shaping the narrowed CW broadband pulse to an arbitrary pulse shape.