Fig. 1. Ellipticity in a spun SMSP fiber.

Fig. 2. Leakage loss of the elliptically polarized eigenmodes in a spun SMSP with α=0.1. Leakage loss is normalized by the cut-off mode leakage loss α of the un-spun fiber.

Fig. 3. Extinction ratio in a spun SMSP fiber. Extinction ratio is normalized by the un-spun fiber.

Fig. 4. Loss ratio between high-leakage and low-leakage elliptically polarized eigenmodes in a spun SMSP fiber.

Fig. 5. Loss ratio between high-leakage and low-leakage elliptically polarized eigenmodes with a normalized spin rate ranging from 0.2 to 0.35.

Fig. 6. Cross section of an SMSP fiber with a depressed elliptical inner cladding.

Fig. 7. Extinction ratio spectrum of a spun SMSP fiber with different spin pitches.

Fig. 8. Loss spectrum of the low-leakage eigenmode in a spun SMSP fiber with different spin pitches.

Fig. 9. Loss ratio between high- and low-leakage eigenmodes in a spun SMSP fiber with different spin pitches.

Fig. 10. Ellipticity of the elliptically polarized eigenmodes in a spun SMSP fiber with different spin pitches.

Fig. 11. Transmitting power in a spun SMSP fiber. Spin pitch, Λ=13.8  mm; fiber length, L=0.23  m; input power, normalized as one unit.