Single-polarization wavelength-tunable fiber laser with a nonreciprocal cavity

Unidirectional, continuously tunable, and polarized oscillation in an erbium doped fiber ring laser is demonstrated without an isolator. Nonreciprocal oscillation is realized with one polarization splitter and two polarization controllers. Fine tuning is realized with fiber birefringence. The laser spectrum is continuously tunable from 1530 to 1560 nm with line widths less than 0.2 nm; the degree of polarization at the output is 92%.<
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