Single-mode fiber optic cable for space applications

Abstract

INTRODUCTION:The advantages of Fiber Optic technology have already been demonstrated with terrestrial communicationsystems and various rapid payout deployment and as such became the corner stone for consideration in satellitesand space station applications. Mainly the key advantages that the fiber is providing are high bandwidth and verylow weight with simultaneous immunity to electromagnetic interference and electromagnetic pulse. In additionthe requirement for continuous performance in a radiation environment of low dose level such as space led us tosponsor a development effort for the design of single mode fiber optic cables to withstand the radiation andenvironmental effects of a space deployment.The program was structured in two parallel phases. The first addresses the fiber and related material optimization.The second phase emphasizes the cable design and related material to ensure a twelve year uninterrupted service.FIBER REQUIREMENTS:The single mode fiber design was selected for this effort since it provides the required bandwidth for high speedsignal processing performed on board space vehicles or space stations.The specific requirements on the fiber design are cited in Table 1.FIBER PHASEIn designing the optical fiber to meet the requirements of space deployment it was decided to build on previousexperience and enhance available designs. The effects of hydrogen-doping on improving radiation sensitivitywere systematically studied with Ge-doped and pure silica core optical fibers. The effects of H2-doping wasstudied on four types of single mode optical fiber and their response to radiation sensitivity from -150°C to