Disclosed is an optical fiber (20) having a centermost laterally-elongated core (30) having a short dimension (a), a long dimension (b) and a first refractive index (n.sub.1), a moat (40) surrounding the central laterally-elongated core, the moat (40) having a second refractive index (n.sub.2), an outer dimension (c) and an outer dimension (d), and a cladding (50) surrounding the moat (40), the cladding (50) having a third refractive index (n.sub.3), wherein n.sub.1>n.sub.3>n.sub.2, a ratio of b/a is between 1.5 and 5.0, and a ratio of d/a is between 2.0 and 7.0. The fiber exhibits polarization maintaining properties in a PMB situated below (i.e., at shorter wavelength than SPB), such that beat length normalized to 1550 nm wavelength is preferably less than 10 mm. The fiber (20) may be coupled to optical components in apparatus where single polarization or polarization maintaining properties are desired.