If an optic cable allows light to escape it may be of no use for data communication but it can make very innovative light sources with virtually endless uses. A 320 mW visible light laser can cause over 200 m (660 ft) of the fiber to glow and, being powered by a sealed battery, it can provide up to three hours of light, safe enough for use in hostile environments, such as with explosive gases, and hardy enough to withstand the worst environments.
The system can be completely portable or permanently installed into a building. The range of fibers extends from ultra thin silica of 0.7 mm (about 1/32 in) diameter for permanent installation in buildings to a highly flexible cable with a plastic sheath giving a minimum bend radius of only 5 mm (1/5th in) and an overall diameter of 8 mm (1/3rd in).
The cladding may consist of materials such as FEP (Fluoro Ethylene Polymer), a plastic similar to PTFE (Poly Tetra Fluoro Ethylene), which has three properties that make it ideal for a wide range of environments. It is very chemical resistant, is unaffected by water and can operate over an extreme range of temperatures. Having read through the above characteristics, it is much easier to think of new uses than it is to imagine lighting situations in which it would not be appropriate. Here are a few applications: marking escape routes for fire fighters; mountain and mine rescue; underwater routes for divers; helicopter landing zones; oil refineries; planes; ships, tunnels. The list is almost endless.