Plastic optical fibers

2004/12/01 Andonegi Beristain, Garazi - Elhuyar Zientziaren Komunikazioa Iturria: Elhuyar aldizkaria

• Unibertsitateak
• Komunikazioak
• Teknologia

Plastic optical fibers are threads of one millimeter in diameter. You can imagine the string of a guitar to make an idea. These optical fibers are currently used in home automation networks, cars, trains and planes.

How is the information transmitted?

On one side of the fiber, at the input end, the light source is placed. Usually it is an LED or laser, which is selected depending on the application. Lasers are faster and can therefore send more information, but they are more expensive.

The light immediately reaches the end of the fiber and the receiver system found in it interprets this signal as 1. However, if the input light source is interrupted, at the end of the fiber there is no light, so the receiving system reads 0.

In this way, images, texts and other types of digitized information are transmitted and encoded using series 1 and 0 in digital systems.

Optical fibers can also be used to make sensors. They are widely used in automotive for safety related sensors. For example, you can know if you need to change the car oil using a fiber-based sensor. The higher the impurity of the oil, the less light passes through. Therefore, if at the end of the fiber not enough light arrives, the sensor gives the oil change signal.

Many advantages

In addition to the different applications, plastic optical fibers have many advantages. They are cheap, to make the fibers is used methacrylate, simple plastic and the connectors they need are simple and cheap. They are also light, a car reduces 50 kg if the communications network is made with plastic optical fibers. And perhaps most importantly, they have no risk of interference, as magnetic fields and other electrical signals do not affect plastic.

But, of course, there is also inconvenience. They are not suitable for long distances, as they present significant losses in light transmission. Consequently, they can have a maximum length of one kilometer, for longer distances glasses are used. In addition, they cannot work more than 80C, since plastic begins to melt and, therefore, lose the transparency necessary for proper transport of light. And if on the road there is a lot of curvature or spirals, light is also lost.

Domestic Research

A research team from the Bilbao School of Engineering works with plastic optical fibers. A simulation software for the propagation of light through fiber has been developed, a tool already used by several companies. In addition, they design and develop new devices based on plastic optical fibers. In addition, a study has been carried out to adapt the fiber network of cars to reduce information losses by volumes, mainly.

• Project title Plastic optical fibers applied to the automotive industry, MOST technology.
• Objective To develop a network of optical communications for the automotive industry.
• Director Joseba Zubia.
• Team J. Arrue, G. Durana, G. Aldabaldetreku, P. Ayestaran, J. Matthew and M. A. Losada.
• UPV Departments:Electronics and Telecommunications. University of Zaragoza: Centro Politécnico Superior.
• Faculty of Engineering of Bilbao.
• MCYT funding.