What colour light from a spectrum best passes through fiber optic cables?

Answer 1

There are many different types of fiber optic cables, and each one has its own special characteristics for passing certain frequencies of light more than others -- depending on what they are used for.

Pure communications cables are geared toward mid infared wavelengths, because the technology to build very high speed comm. mutliplexors and converters exist for those IR frequencies. Lately the technology has improved so higher (near IR) frequencies can be used.

Some newer LASERs are actually fiber optic cables with material "doped" in the cladding. An excitation beam (white visible light) is shined down one end, and it excites the doping material to cause lasing action -- a colored LASER beam exits the other end (most any color is available up to UVA).

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