Patent ID: 6970632

Claim:
An optical fiber, comprising: a centermost laterally-elongated core including a first refractive index (n 1 ), said centermost laterally-elongated core having a short dimension (a) and a long dimension (b), a moat surrounding having a second refractive index (n 2 ) and abutting the central laterally-elongated core, an outer dimension (c) along an axis Xâ€”X aligned with the long dimension (b), and an outer dimension (d) along an axis Yâ€”Y aligned with the short dimension (a) wherein the axis Xâ€”X is generally orthogonal with the axis Yâ€”Y, and a cladding surrounding the moat, the cladding having a third refractive index (n 3 ), wherein n 1 >n 3 >n 2 , a ratio of b/a is between 1.5 and 5.0, a ratio of d/a is between 2.0 and 7.0, and the optical fiber exhibits single polarization propagation within a single polarization band.