Optical coherent technology has been attractive for realizing optical satellite communication, optical beam-former and photonic payload in the future. The radiation resistant test of onboard components was also evaluated as the change of the optical output power, optical spectra and optical frequency noise before and after proton irradiation. As a result, there was no performance degradation due to an aluminum shield with thickness of 4 mm against the proton irradiation corresponding to 15 years of geostationary satellite orbit.