Digital coherent detection and wavelength division multiplexing are promising technologies for achieving throughputs from 100 Gb/s to Tb/s order in optical satellite communications. The adoption of these technologies leads to the possibility of using high performance, low cost commercial off the shelf (COTS) components for satellite communications. In this paper, as COTS optical devices and a DSP-ASIC suitable for enabling 100 Gb/s/wavelength capacity, a micro integrable tunable laser assembly, a lithium niobate modulator, a micro intradyne coherent receiver (Micro ICR) and a DSP-ASIC for 100 Gb/s fiber optical communications were successively exposed to a total fluence of more than p/cm 2 of 70 MeV protons. This fluence is equivalent to the total non-ionizing dose (TNID) and total ionizing dose (TID) experienced during 10 years in low earth orbit. The components were powered, and the performance of a 100 Gb/s signal was measured during irradiation to assess the single event effect (SEE). All components showed no degradation as a result of TNID/TID effects. On the other hand, the Micro ICR and DSP-ASIC showed SEEs which required power cycling of the components to recover their functionality. The SEE affecting the DSP-ASIC also increased the post forward error correction bit error ratio (BER), but the BER nevertheless remained sufficiently low in practice. These radiation test results show that these COTS components can be good candidates for use in satellite communications.