title: Highly efficient Yb-free Er-La-Al doped ultra-low NA large mode area single-trench fiber laser.
abstract: We demonstrate a 60µm core diameter Yb free Er-La-Al doped single-trench fiber having a 0.038 ultra-low-NA, fabricated using conventional MCVD process in conjunction with solution doping technique. Numerical simulations predict an effective single mode operation with effective area varying from 1,820µm(2) to 1,960µm(2) (taking bend-induced modal distortion into account) for different thicknesses of trenches and resonant rings at a constant bend radius of 25cm. Moreover, all solid structure favors easy cleaving and splicing. Experimental measurements demonstrate a robust effective single mode operation. Furthermore, with a 4%-4% laser cavity, this fiber shows a record efficiency of 46% with respect to the absorbed pump power.
authors.forename: D
authors.initials: D
authors.lastname: Jain
authors.forename: S
authors.initials: S
authors.lastname: Alam
authors.forename: Y
authors.initials: Y
authors.lastname: Jung
authors.forename: P
authors.initials: P
authors.lastname: Barua
authors.forename: M N
authors.initials: MN
authors.lastname: Velazquez
authors.forename: J K
authors.initials: JK
authors.lastname: Sahu