[en] The use of fiber optics and microprocessors in a distributed computer control system for a 100-kJ CO₂ laser fusion facility is described. Gas-laser control systems must operate in an environment in which megavolt Marx circuits generate megampere discharges in the laser amplifiers, with attendant high electromagnetic fields. By linking the distributed controls with fiber optics the adverse effect of these fields on the hard-wired controls is mimimized, and the additional advantage of ground isolation gained. Fiber-optic subsystems and interfaces include low-error-rate digital communication links between computers; nanosecond timing and trigger links; fiber-optic parameter monitors with dc-to-10 MHz bandwidths; binary fiber-optic power control for valves, motors, and contactors; and binary fiber-optic status interfaces to monitor the system response to control outputs