And when an amplifier breaks down mid-Atlantic, there's no option but to send out a ship to dredge up the cable. This daunting economic reality is the spur for developing the new generation of fibers. Cambridge, MA-based OmniGuide Communications, founded last year by several MIT professors, claims its new fibers will be able to squeeze losses so low there would be no need for any amplification. What's more, the company says, the usable bandwidth will be substantially larger than in existing optical fibers. It sounds so obvious.
Light travels through air with little scattering.
The answer lies in physics. To achieve the internal reflection necessary to keep light confined in the center of a conventional optical fiber, the cladding has to have a lower refractive index than the inner medium. But all known materials have a higher refractive index than air. So the conventional arrangement doesn't work in making a hollow fiber. Which means an unconventional approach is needed.