<title>Radiation effects in optoelectronic devices</title>

Abstract

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 behavior 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 does of 10<SUP>6</SUP> Gy or neutron fluences of 4 X 10<SUP>14</SUP> cm<SUP>-2</SUP> (1 MeV), respectively. The threshold current of LDs shifted to higher values with increasing dose (<SUP>60</SUP>Co) and neutron fluence. Irradiations of PDs with <SUP>60</SUP>Co gammas up to a total dose of 10<SUP>6</SUP> Gy as well as irradiations with neutrons up to fluences of 4 X 10<SUP>14</SUP> cm<SUP>-2</SUP> (1 MeV) lead to a strong increase of dark current. OCs show a significant reduction of the current transfer ratio at dose values between 10<SUP>3</SUP> and 10<SUP>4</SUP> Gy. Except two types, the optocouplers did not survive neutron fluences &gt;= 8 X 10<SUP>11</SUP> cm<SUP>-2</SUP> (1 MeV).