This paper describes a method to achieve low and stable splice losses in fusion splicing of optical fiber ribbons with CO_2 laser beams Beam power distribution was investigated experimentally. It was confirmed that laser irradiation area expanded to fiber axis and low peak power were effective for low splice losses. In addition, increment of splice losses by fluctuation in the intensity of laser beams and response to it were discussed. The splice loss between 8-fiber ribbons was 0.017dB in the average and 0.010dB in the standard deviation.
