The Fiber Optic Association - Tech Topics
Plastic Optical Fiber (POF)
Plastic optical fiber (POF) has always been "lurking in the background" in fiber optics; a specialty fiber useful for illumination and low speed short data links. There is now a greatly increased interest in POF, as R&D has given it higher performance to go along with its ease of installation and low cost.
POF is large core step-index fiber with a typical diameter of 1 mm. This large size makes it easy to couple lots of light from sources and connectors do not need to be high precision. As a result, typical connector costs are 10-20% as much as for glass fibers and termination may be as easy as cutting with a razor blade! Being plastic, its also rugged and easy to install without fear of damage.
From an optical standpoint,
POF is much lower in performance than glass fiber. It has a loss
of 0.15-0.2 dB per meter at 650 nm and its bandwidth is limited
by its large NA and step-index profile. However, it is adequate
for running short links, such as inside of instruments or within
a room for desktop connections up to 50 meters. And of course
in automobiles, where it has gained a foothold with the new
But recent developments in POF technology have led to low NA POF that offers higher bandwidth and graded-index POF (GI-POF) that combines the higher bandwidth of graded-index fiber with the low cost of POF. Current designs of GI-POF offer up to 2 Ghz bandwidth at distances of 100 meters, but manufacturing problems have hampered its adoption. Recent developments in a new laser (VCSEL of vertical cavity surface emitting laser) promise extremely low cost, high power, high speed transmitters.
POF offers promise for desktop LAN connections. It can be installed in minutes with minimal tools and training. Bandwidth exceeds anyones estimates for the next decade. Prices are competitive with copper. Standards groups are now looking at options for POF. POF could prove the next viable desktop connection.
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