Polymer Optical Fiber (POF for short) looks like a nylon rope, and is transparent to visible light. It is typically made of Polymethyl Methacrylate Polymer (PMMA) as the core material, and a fluorinated polymer as the cladding material.
Light travels inside the core of a polymer optical fiber; the cladding is the external ‘cover” that generates the guiding effect, which forces the light to follow the path of the fiber. Polymer fiber works like a common optical fiber, but there are some significant differences that can be seen in characteristics of POF when compared to other optical fiber.
SIZE PMMA-based POF has a typical outer diameter of 1000µm (i.e. 8 times larger than glass fiber), and a core diameter of 980µm. To obtain a cable, polymer fiber is covered with a 2.2mm-diameter jacket. The material commonly used for jacketing is a High-Density Polyethylene (PE-HD). Due to its small size, immunity to RF noise and its insulating characteristics, plastic fiber cable fits into conduits, in compliance with international standards (EIA/TIA 569, CENELEC EN 50174-2).
BANDWIDTH Polymer fiber is transparent at wavelengths that falls within the visible spectrum. 400-780nm. the most commonly used LEDs and photodiodes work with red light. 650 nm (red).
RELIABILITY Polymer fiber has had great success for reliability in the industrial and automotive markets thanks to its large core size, relaxed tolerances on connetorization and connector misalignment, or resistance to strong vibration environments. The use of visible light allows checking immediately if the cable works, by just looking if light ”comes out” of the fiber end, which express that the system is working.
TERMINIATION PROCCESS The main difference from the common optical fiber and 1mm POF is in the termination process where a simple termination can be done without polishing, where in the field this is a huge advantage. The safety is also an advantage with POF as there are no glass fibers chards to handle and dispose of.
ELECTRICAL INSULATION Polymer fiber doesn”t conduct electrical current, and can be used in flammable or explosive environments.
RESILIENCY In general, Polymer Optical Fiber tolerates bending radii inferior to 20mm, works from -40°C to +85°C. Polymer fiber doesn”t oxidize, withstands humidity and salted atmospheres, offering at least 20 years of working life.
ADVANTAGES OF POF • Easy to terminate • Low cost connections • Durable • Lower systems cost • Easy to handle • Large diameter • Large numerical aperture for easy coupling to sources • Operates in visible range • User friendly