Watts-level, short all-fiber laser at 1.5 mu m with a large core and diffraction-limited output via intracavity spatial-mode filtering

Optical Sciences Center, University of Arizona, 1630 East University Boulevard, Tucson, Arizona 85721, USA.
Optics Letters (Impact Factor: 3.18). 03/2005; 30(4):403-5. DOI: 10.1364/OL.30.000403
Source: PubMed

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.

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