SPIE Optical Systems Design 2012 Injection-moulded 3dB coupler for POF communication M. Haupt and U. H. P. Fischer Harz University of Applied Sciences, Friedrichstr. 57-59, 38855 Wernigerode, Germany Email: mhaupt@hs-harz.de Abstract: POFs (polymer optical fibers) gradually replace traditional communication media such as copper and glass within short distance communication systems. Primarily, this is due to their cost-effectiveness and easy handling. POFs are used in various fields of optical communication, e.g. the automotive sector or in-house communication. So far, however, only a few key components for a POF communication network are available. Even basic components, such as splices and couplers, are fabricated manually. Therefore, these circumstances result in high costs and fluctuations in components’ performance. Available couplers have high insertion losses due to their manufacturing method. This can only be compensated by higher power budgets. In order to produce couplers with higher performances new fabrication methods are indispensable. A cheap and effective way to produce couplers for POF communication systems is injection molding. The paper gives an overview of couplers available on market, compares their performances, and shows a way to produce couplers by means of injection molding. 1. Introduction Polymer Optical Fibers (POFs) offer many advantages compared to alternate data communication solutions such as glass fibers, copper cables and wireless communication systems. In comparison with glass fibers, POFs offer easy and cost-efficient processing and are more flexible for plug interconnections. POFs can be passed with smaller radius of curvature and without any mechanical disruption because of the larger diameter in comparison with glass fibers. The clear advantage of using glass fibers is their low attenuation, which is below 0,5db/km in the infrared range. In comparison, POF can only provide acceptable attenuation in the visible spectrum from 350nm up to 750nm, see fig. 1. The attenuation has its minimum with about 85db/km at approximately 570nm. For this reason, POF can only be efficiently used for short distance communication up to 100m. The disadvantage of the larger core diameter is higher mode dispersion. Fig. 1 General design and attenuation of POF in the visible range [1] The use of copper as communication medium is technically outdated, but still the standard for short distance communication. In comparison, POF offers lower weight and space. Another reason is the nonexistent susceptibility to any kind of electromagnetic interference [1-3]. Wireless communication is afflicted with two main disadvantages. The electromagnetic fields can disturb each other and probably other electronic devices. Additionally, wireless communication technologies provide almost no safeguards against unwarranted eavesdropping by third parties, which makes this technology unsuitable for the secure transmission of volatile and sensitive business information. For these reasons, POF is already applied in various applications sectors.