Patent ID: 7804864

Claim:
An amplification system for outputting pulses having a duration and corresponding pulse width comprising: a modelocked fiber oscillator outputting optical pulses; an amplifier disposed external to the modelocked fiber oscillator and optically connected to said modelocked fiber oscillator to receive said optical pulses, said amplifier comprising a gain medium that imparts gain to said optical pulses; a variable attenuator disposed between said modelocked fiber oscillator and said amplifier, said variable attenuator configured to receive said optical pulses from said modelocked fiber oscillator prior to reaching said amplifier, said variable attenuator having an adjustable transmission such that the amplitude of said optical pulses that are coupled from said mode-locked fiber oscillator to said amplifier can be reduced; and a compressor disposed external to said amplifier to compress the pulses to reduce the pulse width of the pulses, said compressor receiving amplified pulses from said amplifier, wherein said amplifier is configured such that attenuating said amplitude of the optical pulses coupled from said mode-locked fiber oscillator to said amplifier reduces the pulse width at an output of said compressor, and wherein said variable attenuator comprises a polarization selection optics.