A fiber ring laser with tuable wavelength and repetitive frequency is successfully made.The optical pulse with different wavelength transmitting in the fiber chain composed of normal and abnormal dispersion fiber waw researched experimentally and numerically.The results show that with the same initial condition

nonlinear optical pulse transmission in average normal fiber is superior to soliton transmission in short distance.However

soliton transmission is superior to nonlinear optical pulse in long distance.There exists an optimum wavelength with the optical fiber chain composed of normal and abnormal dispersion fibers in long distance transmission.