title: Watts-level, short all-fiber laser at 1.5 microm with a large core and diffraction-limited output via intracavity spatial-mode filtering.
abstract: We report over 2 W of single spatial-mode output power at 1.5 microm from an 8-cm-long, large-core phosphate fiber laser. The fiber has a numerical aperture of approximately equal to 0.17 and a 25-microm-wide core, heavily doped with 1% Er(+3) and 8% Yb(+3). The laser utilizes a scalable evanescent-field-based pumping scheme and can be pumped by as many as eight individual multimode pigtailed diode laser sources at a wavelength of 975 nm. Nearly diffraction-limited laser output with a beam quality factor M2 approximately equal to 1.1 is achieved by use of a simple intracavity all-fiber spatial-mode filter. Both spectrally broadband and narrowband operation of the laser are demonstrated.
authors.affiliation: Optical Sciences Center, University of Arizona, 1630 East University Boulevard, Tucson, Arizona 85721, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Polynkin
authors.forename: Pavel
authors.initials: P
authors.lastname: Polynkin
authors.forename: Axel
authors.initials: A
authors.lastname: Schülzgen
authors.forename: Masud
authors.initials: M
authors.lastname: Mansuripur
authors.forename: N
authors.initials: N
authors.lastname: Peyghambarian