Patent ID: 7529278

Claim:
A mode-lock fiber laser, comprising: an input coupler configured to couple pump light into a fiber laser cavity; a fiber-based gain medium in the fiber laser cavity, the fiber-based gain medium configured to amplify signal laser pulses in response to the pump light, wherein the signal laser pulses each has a peak portion having a peak polarization and a wing portion having a wing polarization different from the peak polarization; a normal (positive) dispersion fiber in the fiber laser cavity, the normal dispersion fiber configured to guide signal laser pulses therethrough; an anomalous (negative) dispersion fiber in the fiber laser cavity, the anomalous dispersion fiber configured to guide signal laser pulses therethrough, wherein the anomalous dispersion fiber is formed by a fiber selected from a group consisting of a Photonic Crystal (PC), a Photonic Bandgap (PBG), and a higher order mode (HOM) fiber, wherein the anomalous dispersion fiber compensates the normal dispersion fiber to produce a net anomalous dispersion; and a first fiber-based polarization controller configured to align the peak polarizations of the signal laser pulses along a first polarization direction; a polarization isolator configured to receive the signal laser pulses from the first fiber-based polarization controller, and to uni-directionally pass the peak portions of the signal laser pulses having the peak polarizations aligned along the first polarization direction, wherein the polarization isolator is configured to block at least portions of the wing portions in the signal laser pulses; a second fiber-based polarization controller configured to control the peak polarization of the signal laser pulses received from the polarization isolator to produce mode locking, wherein the polarization isolator is positioned between the first fiber-based polarization controller and the second fiber-based polarization controller; and an output coupler configured to direct a portion of the signal laser pulses as output laser pulses out of the fiber laser cavity.