A FIBER LASER WITH A COMB-LIKE SPECTRUM

An unpolarized comb-like spectrum is emitted from a fiber laser constr ucted from a Nd-doped silica fiber connected to an undoped high-birefr igence fiber. Depending on the overall birefringence of the high-biref ringence fiber, spectral spacings of 0.8 nm to 4 nm between two adjace nt wavelengths were obtained, with as many as eight simultaneous discr ete peaks. No intracavity polarizing elements were used, and the obser ved spectral characteristics are due to parasitic reflections at the i nterface between the two fibers.