Cladding-pumped optical fiber and methods for fabricating

Fiber optic article, comprising:

• a core;
• a glass cladding disposed about said core and for receiving pump light, said glass cladding having a non circular outer boundary for enhancing the intersection of pump light with said core, said glass cladding including a first index of refraction;
• a glass layer disposed about the cladding, said glass layer having a thickness and second index of refraction, said second index of refraction being less than said first index of refraction;
• and
• said thickness being such that the outer boundary of the glass layer was non circular when said glass layer was conformed to said cladding;
• and
• wherein the outer boundary of said layer is substantially circular.

An optical fiber, comprising:

• a core;
• a glass cladding disposed about said core and for receiving pump light, said glass cladding having a non circular outer boundary for enhancing the intersection of pump light with said core, said glass cladding including a first index of refraction and maximum and minimum diameters;
• a glass layer disposed about the cladding, said glass layer having a second index of refraction that is less than said first index of refraction, said glass layer having an outer boundary having a diameter;
• and
• wherein the ratio of said diameter of said boundary of said glass layer to either of said diameters of said boundary of said glass cladding is no greater than 1.25 and wherein said outer boundary of said layer is substantially circular.