A one-piece connector coupler concept has been developed for optical fiber connection. This coupler employs advanced polymeric material and the techniques of injection molding to produce a low-cost, high performance component that exhibits excellent light throughput characteristics. The adapter uses a novel “leaf-spring” approach to provide the alignment for cylindrical fiber optic termini.This concept has been used to create an ST® coupler. Data will be presented for optical excess loss measurement for multimode optical fibers. Applications for this one-piece adapter will be presented; specifically, the single-piece construction provides unique benefits in instrumentation applications.In addition, this concept can be extended to create new and more capable fiber optic interconnection systems for automotive applications. The production technology developed is ideally suited to satisfy the anticipated high volume requirements for the automotive market.