Effect of reactor neutron irradiation on optocouplers

The reactor neutron irradiation on three types of optocouplers was experimentally studied. Current transfer ratio decreased and saturation voltage increased due to displacement damage in the range of neutron fluence from 3×1011 cm-2 to 5×1012cm-2. The degradation of light emitting diode(LED) optical power, phototransistor gain and photoresponsivity all contribute to the degradation of optocouplers’ performance. The optocouplers with PIN as detector have a much lower current transfer ratio but they are more resistant to displacement damage compared with optocouplers with phototransistor as detector on condition that both kinds of optocouplers use identical LEDs. The radiation tolerance of optocouplers with heterojunction LED is two orders of ma