Multiwavelength erbium-doped fiber ring laser source with a hybrid gain medium

Erbium-doped fiber is a gain medium exhibiting homogeneous line broadening at room temperature, while a semiconductor optical amplifier has a dominant feature of inhomogeneous line broadening. In this work, a semiconductor optical amplifier is incorporated into the cavity of an erbium-doped fiber ring laser to form a hybrid gain medium. Theoretical analysis shows that such a gain medium supports stable multi-wavelength operation. A stable 24 wavelength lasing operation with wavelength spacing of 0.5 nm and signal-to-noise ratio better than 42 dB is observed experimentally at room temperature.