Patent ID: 7526003
Filing Date: 2009-04-28
Classification: H01S

Abstract:
1. A mode-locked fiber laser, comprising: an input coupler configured to couple pump light into a laser cavity; a 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 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 peak portions of the signal laser pulses received from the polarization isolator, wherein the first fiber-based polarization controller, the polarization isolator, and the second fiber-based polarization controller are configured to produce mode locking in the signal laser pulses, wherein the polarization isolator is positioned between the first fiber-based polarization controller and the second fiber-based polarization controller; a mirror configured to receive and to reflect a first portion of the signal laser pulses, wherein the input coupler, the fiber-based gain medium, the first fiber-based polarization controller, the polarization isolator, the second fiber-based polarization controller, and the mirror in part define the laser cavity; and an output coupler configured to direct the first portion of the signal laser pulses to the mirror and to direct a second portion of the signal laser pulses as output laser pulses out of the laser cavity, wherein the output coupler is configured to couple the first portion of the signal laser pulses reflected by the mirror into the laser cavity.