Use of electro-optic techniques to achieve electromagnetic pulse hardness determinations of the effectiveness of optical fiber and hardwired interface technologies in military communication systems in a nuclear environment

Fiber optics will reduce the susceptibility of systems to a direct EMP threat. Cables shorter than 10m present a tradeoff between the shielding effectiveness of standard cables and that of shielding around critical fiber optic receiver components. Long-haul ground systems require only electronics protection; the fiber optic cable is immune to em pickup and need not be buried for protection. Fiber optic susceptibility is less than that of hardwire to burnout and upset in systems that allow an outage time of 1 ms. In a steady-state or low-dose-rate environment, system vulnerability levels depend on fiber response and design margin. A fiber optic interface is feasible which will not fail under the dose rates and total dose levels equivalent to a natural space environment of 0.002 rad(Si) per second for 7 years. Fiber optic system electronics are no more vulnerable to total dose than those of hard-wired systems, which, at practical dose levels of 1 Mrad, do not appear vulnerable. In fiber optic cables, vulnerability level depends on cable type and system design margin. Insufficient data exist to estimate vulnerability levels for the fiber optic systems in displacement damage-producing environments. The report contains a list of 70 references.