A widely tunable narrow linewidth semiconductor fiber ring laser

Abstract
We have demonstrated a novel approach to obtain a 0.1-nm line width laser with 38-dB sidemode suppression by utilizing a 1.3-/spl mu/m semiconductor optical amplifier in a fiber unidirectional ring that consists of a linear polarizer and polarization controllers. The laser has a low-threshold current of 22.5 mA as well as a wide tuning range of 28 nm. The new approach is applicable to the 1.55-/spl mu/m region as well. It is expected that nanosecond wavelength tuning speed is feasible using this approach in conjunction with fast electrooptic polarization controllers, short cavities and low-cavity losses.