Polymer optical fiber

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Polymeric sidelight fibers

Polymer optical fibers ( POF for short , English for polymeric optical fiber or plastic optical fiber ) are optical fibers made of plastic that are primarily used for data transmission, but are also used in the form of side light fibers in (indirect) lighting.

Particularly in short-range data transmission, POF is an alternative to the otherwise most commonly used fiber optics due to its simple assembly .

classification

Application areas fiber types
Fiber type Core / sheath operation area distance Data rates
Mono-mode
fiber 		00,9/125 µm
0,10/125 µm 		telecommunications over 10 km Mbit / s to
Gbit / s
Multi-mode
fiber 		0,50/125 µm
62.5 / 125 µm 		local networks in medium-sized areas,
systems, buildings, telecommunications 		up to 4 km <155 Mbit / s
HCS fiber ,200/230 µm local networks in buildings and industry up to 2 km <100 Mbit / s
POF plastic ,980/1000 µm local networks in buildings, industry and vehicles up to 100 m up to 1 Gbit / s

A distinction is made between the following types of fiber optic cables:

  • Quartz / quartz fiber cable (English Silica-Silica-Fiber)
  • Also PCS cables (HCS, PCF) ( Plastic Cladding Silica Fiber ), this consists of a combination of core glass ( doped , undoped glass) and a plastic jacket
  • APF cable (All Plastic Fiber), the polymer optical fiber (POF).

A distinction is made between the following POF cables:

  • "Single core"
    • Step index (SIF) (SI-POF)
    • Gradient index (GI-POF)
    • Multi Step Index (MSI-POF)
  • "Multi-core"

construction

A common 1 mm polymer fiber consists of a 0.98 mm thick core made of polymethyl methacrylate (PMMA), also polycarbonate (PC) or polystyrene (PS), as well as a 10… 20 µm thick coating (jacket) made of fluorinated acrylate or fluoropolymer , which has a lower refractive index to allow light to be guided through the effect of total reflection in the core. The fiber, including the jacket, is protected by a black plastic sheath that is usually 2.2 mm thick.

The large core diameters allow simple plug connections. Splicing is not common. The maximum operating temperature of standard POF is around 85 ° C.

The following step index fibers are standardized according to IEC 60793-2:

1000 ± 60 µm (category A4a)
750 ± 45 µm (category A4b)
500 ± 30 µm (category A4c)

The numerical aperture of these fibers is 0.5 ± 0.15, the attenuation <40dB / 100m and the bandwidth-length product > 10MHz · 100m.

Advantages and disadvantages

The advantages of POF - similar to glass fiber - are its low weight, its high flexibility and its insensitivity to electromagnetic influences ( electromagnetic compatibility ). Due to the connection technology, which is simple and almost universally applicable compared to fiber optics, POF is used in particular for short data transmission routes, for example within buildings and rooms, within devices, mechanical systems or even cars ( see also: MOST bus ). The intended use can also be the electrical potential separation of high voltage or a source of interference.

The main disadvantages of POF are their high attenuation (approx. 0.1 dB / m at a wavelength of 650 nm) and the technical effort involved in the production of gradient index fibers and single-mode fibers . Due to the high attenuation, the maximum length of the fiber without reinforcement is around 100 to 120 m. A high dispersion and multipath propagation lead to a lower maximum bandwidth length product of a transmission link compared to single mode glass fibers .

Use in data transmission

Rotary encoder with fiber optic cable for rotary data transmission - development at the POF of the TH Nürnberg

In practice, transmission speeds of 1 Gbit / s with a cable length of 50 m are achieved with polymer fibers. In the course of transmission tests with gradient index fibers, 1.25 Gbit / s over 1 km was achieved in 2002 and 10 Gbit / s over 15 m in 2010. In the laboratory experiment, the robustness against bending at 40 Gb / s over 50 m of plastic fiber was examined.

The transmission windows of the step index POF are in the visible range of the electromagnetic spectrum . Light-emitting diodes (LEDs) with a wavelength of 650 nm are usually used as transmitters . Although the blue-green area is also more transparent, efficient and inexpensive emitters have not yet been available, which is why the wavelength range hardly plays a role in practice. In addition, the maximum spectral sensitivity of the receiver is used to silicon - photodiodes also on the long-wavelength end of the light spectrum.

The coupling of light-emitting diodes with standard polymer fibers (POF with a core diameter of 1 mm and an outer diameter of 2.2 mm) can, for example, be carried out by means of a sleeve with a lens molded onto the LED, in front of which the polished or simply cut fiber end is fixed. In addition, there are plug-in systems for repeated use, which are used, for example, for digital audio signal transmission ( see also: Toslink ). With thinner, less dispersed gradient index fibers, laser diodes are also used as transmitters.

For POF cables there are TOSLINK and special HFBR and OVK plugs, as well as SMA, F-SMA, EM-RJ and the ST plugs as well as POF connectors, plugless and FO5, FO7 plugs, are also available available.

Former products

GRINIFIL was the protected brand name of a group of optical fibers that were called plastic optical fibers in the GDR .

literature

  • Ernst Ahlers: Network of light - home networking with light-conducting plastic fibers. In: c't . 3/07.
  • I. Möllers, D. Jäger, R. Gaudino, A. Nocivelli, H. Kragl, O. Ziemann, N. Weber, T. Koonen, C. Lezzi, A. Bluschke, S. Randel: Plastic Optical Fiber Technology for Reliable Home Networking - Overview and Results of the EU Project POF-ALL. In: IEEE Communications Magazine. Optical Communications Series, Vol.47, No.8, pp. 58-68, August 2009, doi : 10.1109 / MCOM.2009.5181893 .
  • Olaf Ziemann, Jürgen Krauser, Peter E. Zamzow, Werner Daum: POF manual - optical short-range transmission systems. 2nd edition, Springer-Verlag, 2007, ISBN 978-3-540-49093-7 .
  • Olaf Ziemann, Jürgen Krauser, Peter E. Zamzow, Werner Daum: POF - optical polymer fibers for data communication. Springer, 2001, ISBN 978-3-662-09385-6 .
  • SCJ Lee: Discrete multitone modulation for short-range optical communications. Dissertation, Technische Universiteit Eindhoven, 2009, online (PDF; 12.51 MB), ISBN 978-90-386-2115-9 , doi : 10.6100 / IR656509 .

Web links

Individual evidence

  1. ↑ a b Edgar Voges, Klaus Petermann: Optical Communication Technology: Manual for Science and Industry , Springer-Verlag 2019, 1110 pages, page 297
  2. ↑ Present State-of-the-Art of Plastic Optical Fiber (POF) Components and Systems. White Paper of the Plastic Optical Fiber Trade Organization, 2004, p. 4 ( PDF , typical transmission spectrum).
  3. ↑ H. Yang, SCJ Lee, CM Okonkwo, ST Abraha, HPA van den Boom, F. Breyer, S. Randel, AMJ Koonen, E. Tangdiongga: Record high-speed short-range transmission over 1 mm core diameter POF employing DMT modulation . In: Optics Letters . tape 35 , no. 5 , 2010, p. 730-732 , doi : 10.1364 / OL.35.000730 .
  4. ↑ Schöllmann, S .; Rosenkranz, W.; Wree, C .; Joshi, A .: First Experimental Transmission over 50 m GI-POF at 40 Gb / s for Variable Launching Offsets in Proceedings of the 33rd European Conference and Exhibition of Optical Communication 09/16/2007 - 09/20/2007 Berlin
  5. ↑ HFBR connector on itwissen.info, accessed on March 4, 2017.