The Effects Of Radiation On Optoelectronic Devices

Abstract

The application of fiber optic links in both commercial and military space systems, as

Effects of radiation on laser diodes.

“…Because many laser diode operating parameters show a postirradiation change that is a function of Φ K 0 τ , the factor K 0 τ can be used as a measure of radiation sensitivity. 18 For example, the increase in the threshold current due to radiation is proportional to Φ K 0 τ . 18 The damage constant K, which is largely determined by the type of radiation and the material composition, 19 essentially gives the number of nonradiative centers introduced per unit fluence or dose of radiation per second.…”

“…18 For example, the increase in the threshold current due to radiation is proportional to Φ K 0 τ . 18 The damage constant K, which is largely determined by the type of radiation and the material composition, 19 essentially gives the number of nonradiative centers introduced per unit fluence or dose of radiation per second. 18 Since the radiation hardness of different materials may be compared by calculating their K 0 τ values, the quantity 1/ K 0 τ can be interpreted as a threshold fluence at which a shift in threshold current becomes noticeable.…”

“…41 Also, the parallel between reduced temperature sensitivity and less susceptibility to radiation damage suggests that continued improvement in laser diode operating characteristics will be accompanied by improvement in radiation hardness. 19 Neutron bombardment also reduces the light output of laser diodes due to permanent radiationinduced lattice damage. 19 However, at operating currents well above J th , the decrease is relatively insensitive to dose.…”

“…19 Neutron bombardment also reduces the light output of laser diodes due to permanent radiationinduced lattice damage. 19 However, at operating currents well above J th , the decrease is relatively insensitive to dose. 18 This is because of the very short radiative lifetimes (about 10 -11 s) during intense laser operation.…”

“…18 The damage constant K, which is largely determined by the type of radiation and the material composition, 19 essentially gives the number of nonradiative centers introduced per unit fluence or dose of radiation per second. 18 Since the radiation hardness of different materials may be compared by calculating their K 0 τ values, the quantity 1/ K 0 τ can be interpreted as a threshold fluence at which a shift in threshold current becomes noticeable. 17 Much of the available data on radiation effects in laser diodes (see Table 2) was obtained using older, low-power devices, but most of the general trends are also applicable to newer devices.…”