Patent ID: 7822077
Filing Date: 2010-10-26
Classification: G02B,H01S

Abstract:
1. A method of fabricating a fiber amplifier generating laser light in response to pump light from a pump source, the method comprising: forming a large mode area (LMA) core; and forming a confined region having a predetermined area within the LMA core and a predetermined doping concentration of thulium ion (Tm wherein a ratio of the predetermined area of the confined region and an area of the LMA core, and the predetermined doping concentration of Tm are selected in order to achieve a predetermined Quantum Efficiency (QE) gain greater than a factor of 1, the QE gain defined as a ratio of emitted photons to absorbed pump photons, and wherein the forming of the confined region further includes forming the confined region so that a propagating signal mode supported by the LMA core substantially overlaps the confined region containing the predetermined doping concentration of Tm wherein the forming of the LMA core further includes adding additional constituents other than Tm