A “creativity-friendly” kit for technicians, experimenters, scientists and enterprising students who require prototypes or special-purpose interfaces requiring fiber optics capabilities. This very low-cost “active link” requires a single +5 volt supply and interfaces with all TTL/CMOS logic. It includes 10 meters of 1000 um optical cable; efficient, dry, non-polish connectors, bulkhead interfaces, and splices; integrated detector (s) and emitter(s); and top-quality printed writing boards. Full instructions and technical data sheets complete the package. The operable range of both kits can be extended to 60 meters with additional cable purchased separately. The Designer’s Kits have been the basis of many fiber optics “brainstorms.”