title: Absorption and emission properties of Tm2+ ions in germanosilicate glass fibers.
abstract: Absorption and emission properties between 350nm and 1600nm of the Tm2+ ions in optical fibers were investigated using the Tm2+-Tm3+ co-doped germanosilicate glass fibers and its fiber preform. Strong broad absorption band due to Tm2+ ions was found to appear from 350nm to ~900nm together with the absorption bands due to Tm3+ ions. Broad emission from ~600nm to ~1050nm and the other emission from ~1050nm to ~1300nm, which were not shown in the Tm3+ ions, were found upon the Ar ion laser pumping at 515nm. Both absorption and emission results confirm that the Tm2+ ions in the germanosilicate glass have the 4f-5d energy band from 350nm to ~900nm and the 4f-4f energy level at ~1115nm.
authors.forename: Yune Hyoun
authors.initials: YH
authors.lastname: Kim
authors.forename: Un-Chul
authors.initials: UC
authors.lastname: Paek
authors.forename: Won-Taek
authors.initials: WT
authors.lastname: Han
authors.forename: Jong
authors.initials: J
authors.lastname: Heo