Radiation effects in optoelectronic devices

Active optoelectronic devices such as light emitting diodes (LEDs), laser diodes (LDs), photodiodes (PDs), and optocouplers (OCs) were evaluated for degradation under gamma, 14 MeV neutron, and flash X-ray irradiation. Dose rates, total dose values, and neutron fluences were chosen such that we get estimates of the behaviour especially in space environments and nuclear engineering. The devices are designed for wavelengths from 660 to 1550 nm. LEDs showed a decrease of output power between 0.1 and 28 dB after a total gamma dose of 10E6 Gy or neutron fluences of 4x10E14 cmE-2 (1 MeV), respectively. The threshold current of LDs shifted to higher values with increasing dose (60Co) and neutron fluence. Irradiations of PDs with 60Co gammas up to a total dose of 10E6 Gy as well as irradiations with neutrons up to fluences of 4x10E14 cmE-2 (1 MeV) lead to a strong increase of dark current. OCs show a significant reduction of the current transfer ratio (CTR) at dose values between 10E3 and 10E 4 Gy. Except two types, the optocouplers did not survive neutron fluences < about 8x10E11 cmE-2 (1 MeV).