Fibre Optics Principles and Applications of Fibre Technology for Transmission of Light

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1 Fibre Optics Principles and Applications of Fibre Technology for Transmission of Light Background information: Fibre Optic technology has many important applications which make use of the reflective properties of certain substances such as glass, silica and certain plastics. The uses range from medical applications (eg in surgery), industrial sensing equipment, decorative lighting, and telecommunications and data transmission. One of the great values of fibre optic technology is its capacity reach and traverse inaccessible, difficult and extreme environments. Telecommunications provide some of the best known applications of fibre optic technology, and is specifically referred to in the Applied Science GCSE specifications. In order to understand how fibre optics work it may be useful to consider its applications in lighting. The visible radiation illustrates the principles applying to all fibre optics including telecommunications. This activity is intended to be supported by the Schott Easy-Fit Star Kit leaflet provided with the trial pack

2 An Industry Context The Doncaster based Schott Fibre Optics Division is part of the international Schott Group of companies. The Doncaster operation specialises in Fibre Optic Lighting, including decorative and display lighting, and lighting systems for BMW cars. The company uses glass fibres which have the best optical properties (refractive index) for transmitting visible light, whereas silicas (lower refractive index) are better for telecommunications. A range of useful, and visually attractive information about fibre optic lighting can be found at the Schott website with access to their online magazine at This contains a range of interesting articles, often with excellent scientific content.

3 Curriculum Ideas: Assist understanding of fibre optic technology and how wave forms and data are transmitted, by illustrating the technology through fibre optic lighting. Fibre optic lighting is not as energy efficient as ordinary light bulbs, and certainly cannot match low energy light lamps, in terms of electrical energy costs and efficiency. However, there are situations where fibre optic lighting provides an ideal solution because of its special properties. Some key properties of fibre optic lighting are shown in the table below. Discuss these features and suggest situations where fibre optic lighting might be useful, even though it is more expensive. (Details in red are examples for information). Some of the information in the table could be omitted for pupils to complete their own ideas, as appropriate. (The Schott leaflet Schott Easy-Fit Star Kit could be used as background source material to help this activity)

4 Properties and Applications of Fibre Optic Lighting Property of fibre optic lighting The light source (electrical power source) is at one end of the fibre, while the light is emitted from the other end of the fibre (can be many metres away Situation where it is useful Lighting in inaccessible places, eg very high ceilings, outside of tall buildings Reason for using fibre optic rather than ordinary lighting No difficulty in changing bulbs / replacing light source, since this can be located somewhere easy to reach The point at which light is emitted is cold. Heat is only produced at the light source, not where the light shows (Ordinary light bulbs get hot) Lighting food freezer cabinets Lighting shop display cases which people might touch (eg jewellery, ornaments) No risk of frozen food being heated in the freezer No risk of customers burning themselves Lighting in areas with flammable or other hazardous material No fire risk at point of light emission One light source can provide lighting through a bundle of fibres, each one of which will emit its own point of light Decorative lighting Theatrical lighting effects The flexible fibres can be spread out to create any desired pattern. Also, since all points of light operate from one source, you never have a problem with individual bulbs blowing. The light source is easily replaced

5 The fibre transmits visible light radiation. There is no electrical current in the fibre Lighting in wet environments, (eg under water) Water conducts electricity, making electrical appliances very dangerous in wet conditions. In fibre optics there is no risk of electrocution as the electric light source is kept in a safe dry environment. The fibre and its light emitting end carry no current, and so can go anywhere The light transmitting fibre can be very thin and flexible Medical uses, (eg allowing surgeons to see inside the body through a very small hole, instead of needed to open up the patient Using a light source outside the body, light can be transmitted along some thin fibres inserted into the body. Special design allows other parallel fibres to carry reflected light from inside the body back to a camera or screen for the surgeon to see what is inside (Note no danger of heat or electrocution)

6 Further Activities/Curriculum links The Schott Easy-Fit Star Kit leaflet includes some information about the Technical Specification of the equipment, including wattage, lamp life and working voltage. Pupils could research a range of other types of light bulbs (eg ordinary household filament bulbs, low energy lamps, fluorescent tubes) for similar information eg. In table form: Type of lighting/bulb Schott Easy-Fit Star Kit Wattage Voltage Lamp life (if known) hours

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