Impact of neutron irradiation on optical performance of InGaAsP laser diodes

Radiation damage of InGaAsP laser diodes by high-temperature gamma-ray and electron irradiation

“…As shown in figure 2, the optical power decreases after a 1-MeV fast neutron irradiation at room temperature, while the threshold current increases [2]. The reason for the positive shift of the threshold current is mainly related to a decrease of the electron density due to the formation of radiation-induced lattice defects in the In 0.76 Ga 0.24 As 0.55 P 0.45 multi-quantum well active region.…”

“…These deep levels are thought to be associated with a Ga vacancy. The decrease of optical power is related to the induced lattice defects in the In 0.76 Ga 0.24 As 0.55 P 0.45 multi-quantum well active region, causing a reduction of the non-radiative recombination lifetime and of the mobility due to carrier scattering [2]. One can calculate the damage coefficient of P L at I F = 20 mA for different radiation sources at room temperature irradiation, defined by the following equation [3].…”

“…Figure 1 shows the schematic structure of the used InGaAsP laser diodes. More detailed on the diode process are described in previous paper [2]. Before and after irradiation, the current/voltage (I/V) and capacitance/voltage (C/V) characteristics of the diodes were measured at room temperature.…”

“…Therefore, it is worthwhile to investigate the operation of such photodevices in a radiation environment. Some results on the radiation damage of laser diodes by proton and neutron irradiation have been reported before [e. g. [1][2].…”

“…The data are compared with previous neutron irradiation results [2]. In addition, the impact of the irradiation temperature is investigated, to assess the device behaviour in extreme space conditions (100 and 200 o C ).…”