Visible regions, glass optical fibers

Fiber optics may be purchased that transmit radiation firom the ultraviolet (190 nm) to the infrared (>5 /x.m), but each has a limited range. Plastic and compound glass materials are used for short distances in the visible region, while silica fibers can be used from the UV through the near-IR (2.3 /rm) regions, but they are very costly. Fluoride and calcogenide glasses extend farther into the infrared. 

The material of which the optical fiber is made determines the excitation wavelength range used. Fused silica, glass, and plastic fibers are the most common fiber materials. Silica can be used from the ultraviolet range down to 220 nm, but the fibers are expensive. Glass is suitable for use in the visible region and is lower in cost than silica. Plastic fibers are even less expensive but are limited to use above 450 nm. 

Optical fibers can be plastic, i.e. methacrylate, or inorganic, i.e. glass for the visible spectral region and quartz for the UV region and range from 8 to 1000 pm in diameter. Some manufacturers use color codes to facilitate their identification (Figure 5.11) [2]. 

The optical region of the spectrum where fiber-optic devices operate is from 300 to 2 pm wavelengths. The wavelengths used in fiber-optic systems are matched to the particular characteristics of the system. Plastic fibers operate best at visible wavelengths, non-silica glass fibers are designed to operate at infrared wavelengths, and... 

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