POLARIZATION-MAINTAINING GAIN OPTICAL FIBER HAVING ELLIPTICAL CLADDING AND LARGE MODE FIELD DIAMETER

摘要

The present invention discloses an elliptical cladding polarization-maintaining large-mode-area gain fiber, structurally comprising a core of the elliptical cladding polarization-maintaining large-mode-area gain fiber, an inner cladding, an elliptical stress layer, a first outer cladding, a second outer cladding and a third outer cladding, wherein the inner cladding surrounds the core; the elliptical stress layer surrounds the inner cladding, and has an elliptical cross-sectional shape; the first outer cladding surrounds the elliptical stress layer; the second outer cladding surrounds the first outer cladding; and the third outer cladding surrounds the second outer cladding. As the birefringence of the elliptical cladding polarization-maintaining fiber is directly proportional to the ellipticity and the deposition of a stress-applying area occurs during the preform rod forming process, procedures of preform drilling and the like are eliminated, and the likelihood of preform contamination is greatly reduced. The optical loss and strength of the fiber can hence be improved, and the entire manufacturing process is simplified. Furthermore, the birefringence and the pump absorption of the fiber can also be improved.