Brief History:
It all started with John Tyndall who discovered reflection within a water stream back in 1854. Fiber Optic technology was first used in 1880 with Alexander Graham Bell's invention of the "Photophone." At the same time, William Wheeler patented a mechanism for piping light through tubes lined with a highly reflective coating. Nearly fifty years later, the term "fiber optics" was coined (1954) and the idea of cladding individual fibers was first proposed. The first commercial optical fibers were manufactured by Corning in 1975 and mainly were marketed though tacky "Anemone" lamps. Today's fiber optics have significantly increased their efficiency with below 150 dB/Km loss compared to a loss of 20 dB/Km features in the mid-seventies. Glass fiber optics is now in its fourth decade of use, while plastic fiber optics is making great advances to also join this exciting field.

Innovation:
The light source is placed away from where the illumination is required, but in a location always convenient for its renewal. Actual light rays conducted to where needed along a series of fiber optic light guides using total internal reflection.

Components:
light source + harness + light guide + fixtures & fittings = fiber optics

Function:
To understand how fiber optics works, it is easier to look at each of the components separately.

Light source:

The primary illuminators (or light sources) used in fiber optics are Metal halide and Quartz halogen lamps. Illuminators are the source of the light that travels down the fiber optic conduits. The Metal Halide lamps feature a long life (5000-6000hrs on 150 WMH) and high efficiency. Compared to the shorter life tungsten or quartz halogen lamps, however, the metal halides demonstrate higher cost for replacement and lower CRI (color rendering index). Quartz Halogen illuminators feature a CRI in the 90's and thus are recommended for use when color rendering is important. The illuminator can be stored in a metal container about the size of a shoebox. New kinds of metal halide lamps can provide brighter light and be house in a smaller container, but cannot be used with plastic fibers that are not able to withstand the heat and the UV rays of the lamp. Lamps whose light rays scatter in many directions (not in a narrow, focused beam) are inefficient. One illuminator can efficiently light several applications. For example, a metal halide projector can power a maximum of 160,000 glass strands in any combination of tail sizes while a tungsten source can accommodate 135,000 strands. Illuminators also house the color wheels that allow fiber optics to change color.

The light source should be wired to internal exhaust fan running at a regular speed. As a safety precaution, the lamp will automatically turn itself off when the heat reaches a certain level. Due to this built-in feature, when more than one projector is installed in same place, the heat exhaust from one must be directed away from the other.

Harness:

Glass or plastic fibers (also called tails) are gathered in a bundle that is called a harness. These factory-assembled harnesses deliver the light to where it is needed. One end is fixed permanently into a common end that is inserted in to the projector, while the other end leaves the tails free to be manipulated in any fashion. The harness maximizes performance and dramatically simplifies the system installation.

Light Guide:

There are two types of tails-end-emitting (size 1-380) and side-emitting (size 1-8) . An end-emitting tail is covered with an opaque sheathing ranging from PVC, Megolon, silicon (providing extra flexibility), and metal (protects tails where they are subject to damage). The refractive index of the cladding is made smaller than the core to keep incident light ray reflecting where the core and the cladding emet, and down the fiber. The opaque sheathing prevents light from exiting until the very end of the fiber. Without an opaque sheathing, light emerges from all sides of the fiber and is referred to as a side-emitting tail.

There are limitations to the length of the tails. Attenuation, or the inevitable loss of light as it travels along its path, needs to be taken into consideration. If color rendering is important, glass tails should be no longer than 8 to 10 meters (24-30ft) in length. This figure can be up to 20 meters if the tails go in opposite paths out of the illuminator. The quality of the glass (or plastic) also contributes to the rate of attenuation in the fiber . Longer lengths of 12 to 15 meters (up to 45 ft) can be used if color is not an important factor (i.e. emergency lighting). With a single projector, the maximum length of a plastic fiber is 40 feet. Side-emitting plastic fibers can run up to 30 meters (nearly 100ft) provided that it is fed from both ends of two sources. Plastic fibers can withstand heat up to 100 degrees Celsius. The use of a glass coupler with the plastic fibers aids with heat isolation to keep the fiber interface as cool as possible and have UV rays filtered out. The loss of light in transmission along the (glass) fiber is exponential. Not only does one have to consider the attenuation along the fiber but slight losses at the entrance and the exit of the light. A larger size fiber may be chosen for a very long length to help compensate for attenuation. Using multiple tails focused on the same object can increase intensity. The same can be achieved in glass fibers by using collimating lenses, although the footprint of the light is reduced. If uncontrolled by lenses, the cone of light emerging from all end-emitting tails is always 68-70 degrees, while the footprint of the light increases with the size of the tail.

Fixtures & Fittings:

Individual points of light can be colored , controlled, or altered, by attaching lenses to the threaded metal ferrules at the end of each light. The lenses are made of high-quality polished glass, yet one should keep in mind that everything is magnified, including any discrepancies. Lenses are not always necessary. Lenses can be easily installed or removed by screwing them on/off the metal ferrule. The different types of lenses include: collimating (narrows beam), diffusing (spreads the beam), downlight (light travels straight down from ceiling), wall-washer (covers an expanse of wall evenly), framing projector (restrict light to specific shape ), and zoom lens (either pinpoint or larger spotlight).

Tracks, clips, mounting brackets and other accessories are an important part of the installation process. Track is a convenient method of mounting straight runs of linear light optical fibers to a flat surface. Tracks can be UV stabilized and used in either indoor or outdoor applications. Polymer clips can be used for flush mounting. Waterproof and vandal proof fittings are also available enabling under water and floor/pavement fittings (respectfully). There is a wide array of accessory items that can be adapted to any customized plan.

Benefits:

· Fibers do not conduct UV radiation: it is safe to use to light objects sensitive to UV radiation
· Fibers do not conduct IR radiation: no heat is conducted through the system that can be damaging to heat sensitive materials.
· Fibers do not conduct electricity: there is no electrical or fire hazard at the location of the fiber optic fixture.
· Fixtures are very small: they can be designed for intense and controlled light output: can light areas that could not be easily illuminated before (edge lighting).
· Light source located away from the actual fixture: lamp replacement does not effect the area being lit. Also, controlling the light from the source allows for synchronized changes (color, intensity, or effects) of many fixtures.
· Reduces energy consumption: less energy is needed for air condition in because fiber optic lighting systems emit less heat than conventional systems. (According to Jack Miller, vice president of NoUVIR Research, "Replacement of halogen track lighting with… fiber-optic systems usually results in energy saving of 50% to 70%.")

Glass vs. Plastic Fibers:

· Longevity: plastic fibers are affected by heat and UV rays from the lamp even with the use of a buffer. Due to this deterioration, plastic fiber optics will eventually lose the ability to carry light, stiffen, discolor, or melt.
· Color rendition and light levels: glass fibers are the best conductor of light. Clarity, color rendition, and light levels are typically better in glass fibers.
· Selection of light sources: new more efficient halide lamps developed can only be used with glass fibers since plastic fibers can be damaged by the IR and UV rays of lamp.
· Environmental impact: the components of glass fibers are green, while plastics emit poisonous fumes when burning.
· Installation: glass fiber optics are precut at a factory and cannot be shortened, lengthened, or cut onsite. Plastic fibers can be cut onsite.
· Costs: initial costs are about the same according to Gersil Kay. Boston Optical Fiber (a plastic fiber optics producer) claims that glass fiber optic installation is extremely expensive to install and maintain.
· Reusability: glass remains supple, while plastic may "freeze" in the shape it is initially installed.
· Maintenance requirements: regular maintenance of glass fibers is minimal (dusting of projector). For plastic fibers, the disintegrated parts of the fibers need to be trimmed off regularly.

Application:

End-emitting tails that produce directional light have many practical applications. Glass end-emitting tails used in a grid pattern provides ambient down-light. A large, plastic end-emitting solid-core can be used for similar purposes. The solid core, which is not multi-fiber in nature, is not likely to break on accident, yet it is not as flexible as small plastic or glass fibers. Both glass and plastic side-emitting tails as well as small end-emitting plastic tails are for decorative purposes only because they cannot provide even overall illumination.

Typical illumination applications include:

· Display and exhibit lighting: replace traditional linear fluorescent and MR 16 lighting
· Water: light pools, spas, fountains, saunas, waterfalls, and linear lighting along pool edges. · Architectural highlighting: emphasizes the architectural features of a room or outline the exterior contours of entire buildings.
· Signage and visual guidance: used to light a variety of signs or in edge-lit exit signs, billboards, and traffic signals.
· Vehicle: used for backlighting applications and drive indicator lights.
· Downlight and ambient: used in restaurants and offices
· Landscaping: in-ground landscape lighting
· Perishables: provide lighting for food stuffs, tobacco goods, cosmetics
· Hazardous area zones: provide lighting in inhabitable areas
· Decorative: special effects such as color changes and strobing.
More specific applications include the lighting of entire glass block walls, cove lighting, and step lighting.

Future Application:

Magnum hypothesized that "Fiber-optic systems have not made much headway into the general lighting market… [due] to technical limitations and high cost of the materials involved. (Lightly Expressed Ltd.)". That is bound to change with upcoming advances in fiber optics. Liquid Core and Polymer Optical guides (pictured below) are entering the market with features such as providing brighter light than glass light guides do and more uniform side-lighting applications.

Fiber optics is not limited to illumination alone. To communicate with a fiber optic, the light is rapidly switched on and off, sending a digital signal. It is used to transmit light, data, and communication. The bandwidth of a fiber is the amount of data a cable can carry (bits/second). A larger bandwidth means greater potential data-transmission capability . The applications of fiber optics in this market are very diverse. Small offices and home offices, corporations, and businesses can use optic fibers to affordably maintain secure, high-bandwidth LAN 's for both internal and external communications. Fibers can be used to support two-way information transfer, internet access, and a variety of mobile computing tasks. The military has started to experiment with smart suits that are wearable, water-resistant, lightweight, computing devices. Ultimately, the benefits of glass and plastic fiber optics will be combined in an intricate network. "The design is to have single mode glass fiber outside the home connecting to a plastic fiber network within the home" -Boston Fiber Optics.

Contact:

There are numerous web sites concerning fiber optic product information. http://www.optical-engineer.com/lighting/index.htm#Fiber%20Optics has links to several of these pages under the sub-heading "fiber optics."

Glass Optical Fiber

Corning Inc
http://www.corningfiber.com/
TEL: 1-800-525-2524 ext. 7516
FAX: 1-800-539-3622
E-MAIL: info@corningfiber.com

Schott Fibre Optics (UK) Ltd
http://www.schott.co.uk/
TEL: +44 - 1302 361574
FAX: +44 - 1302 340803

Plastic Optical Fiber

Boston Optical Fiber (BOF)
http://www.bostonoptical.com
CONTACT: Boyd Corbett
TEL: 1-847-776-1997
FAX: 1-847-776-3550

Lymenyte International Corporation
http://lumenyte.com/
TEL: 949-829-5200
FAX: 949-829-5201
E-MAIL: licinfo@lymenyte.com

Translight Inc
Division of Fiberoptics Technology, Inc.
http://users.ntplx.net/~translit/
FAX: 1-860-928-7664
TEL: 1-800-433-5248

Fiber Optic Lighting Systems

Creative Optics
http://www.compusmart.ab.ca/hbens/
TEL: 1-403-434-6073
E-MAIL: hbens@compusmart.ab.ca

Fiberoptic Technology Inc. (FTI)
http://users.ntplx.net/~fiber/
TEL: 1-800-433-5248
FAX: 1-800-543-2558

FiberStars
http://www.fiberstars.com/
TEL: 1-800-327-7877
FAX: 1-510-490-3247
E-MAIL: generalinfo.cl@fiberstars.com

Lightly Expressed Ltd.
http://www.lightlyexpressed.com/
VOX: 1-540-387-2104
FAX: 1-540-387-2105
E-MAIL: information@LightlyExpressed.com

Unison Fiber Optic Lighting Systems
http://www.unison9.com/
TEL: 1-440-519-1033
FAX: 1-440-519-1038
Email: unison@unison9.com

Bibliographical sources:

Kay, N. Gersil, Fiber Optics in Architectural Lighting, McGraw Hill Companies, 1999, New York Thorsen, Norma, Fiber Optics, Prentice Hall PTR, 1998, Upper Saddle River NJ http://lumenyte.com/
http://users.ntplx.net/~fiber/
http://users.ntplx.net/~translit/
http://www.bostonoptical.com
http://www.compusmart.ab.ca/hbens/
http://www.corningfiber.com/
http://www.fiberstars.com/
http://www.lightlyexpressed.com/
http://www.lrc.rpi.edu/Projects/fiber97.html
http://www.optical-engineer.com/lighting/index.htm#Fiber%20Optics http://www.schott.co.uk/
http://www.swinter.com/projects/fiber_optic_daylighting.html
http://www.unison9.com/