Tuning characteristics of fiber ring semiconductor lasers

A novel appro ach to achieve single frequency,widely tunable semiconductor laser oscillation is put for ward. One appropriate candidate is a fiber ring semiconductor laser( FRSLs) with a semiconductor gain medium and an external cavity. The threshold current and output power with tuning wavelengths of FRSLs is experimentally studied. The sing lemode oscillation is demonstrated and dynamic tuning of FRSLs is realized. The output optical pulses have been tuned over a wavelength range of 36nm. The analysis confirms that there is an optimum coupler splitting ratio to trade off between wavelength tuning width and output power. The experimental results ar econsistent with theoretical simulation results.