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Introduction to Fiber-Optic Lighting - Fibers The fibers are used to transport the light from the illuminator to where it is used. They may be side-emitting, which means the light is emitted from the fibers themselves, or end-emitting, meaning the light is emitted from the output end of the fibers. Multiple fiber strands are typically grouped together or bundled to operate as a single fiber. The bundle's common end is attached to the illuminator's port(s) to receive light from the lamp, then transmit the light through the length of the material. If this is an end-emitting fiber, a ferrule may be used at the output end to hold the bundle in place. If this is a harness system, the fibers may branch into multiple fibers or fiber bundles, called tails, to create multiple light sources. Fiber construction may be plastic or glass (ensure that the illuminator and the fibers are compatible). Illuminators are available that operate with both. Below are several areas of comparison: Color shift: Some types of plastic fibers can experience color shift to yellow, while certain other plastic fibers and low-quality glass fibers can experience color shift to green as the light is transmitted through the material, which may pose a problem for some applications. The degree of color shift is based on the length of the fiber. If these fibers are used, shorter lengths or fiber can be specified or a color-correcting filter.· Heat: The fibers must withstand heat emitted by the lamp that impacts the input end of the fiber. Glass can handle higher temperatures than plastic.· UV: Glass absorbs ultraviolet wavelengths over a few feet of the fiber, while some plastic fibers are very sensitive and can be damaged. For these fibers, a UV filter is recommended.· Fiber cutting and bending: Plastic fibers can be cut to specified lengths at the job site (it must be a very clean cut), while glass fibers, requiring harnesses, are usually custom-produced by the manufacturer. Glass fibers are more easily bent, although if bent too far they can break. Some plastic fibers can also break if bent too far. The degree of bending is very important. Curves reduce the amount of light transmitted, and an angle that is too steep will result in very little light at the end. Consult with manufacturers carefully as to the proper radius of the curves for a particular product.· Price: Glass fibers
generally cost more than plastic fibers.Fixtures Light "Rope": The fibers themselves can be considered a light fixture if they emit light in architectural detailing, signage and other applications traditionally dominated by neon. Downlights: These compact fixtures, typically constructed of cast aluminum or molded plastic, are available in many finishes and colors. Decorative fixtures pass the light through acrylic molds, crystals or clear, colored or frosted glass to produce various effects. Accent/Wall Wash: These socketed, adjustable fixtures are often used in display lighting and for wall washing. They often include a lens that enables the designer to adjust the beamspread from narrow to wide. Underwater: These fixtures include a lens to make the fixture waterproof.· Specialty: These small decorative fixtures are designed to work with tiny points of light and usually include "bullets" and "icicles" made of shaped glass. Fiber-optics article sections |
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Image courtesy Fiberstars Above: example of fiberoptic cables used for end lighting. Image courtesy Fiberstars |
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