These devices can be fusion spliced together to maintain a low gap loss after generating a quality cleave in them using the scribe-and-tension method. These devices are produced from multi-story draw towers. Erbium-doped amplifiers are used in conjunction with these devices to prevent degradation and allow them to leverage wavelength-division multiplexing. The acceptance angle of these devices corresponds to their numerical aperture. Dispersion limits the maximum length (-5[1])of the multi-mode types (-5[1])of these waveguides, (-5[1])which (-5[1])have a higher ratio of core to cladding diameter (10[1])than their single-mode type. For 10 points, total internal reflection confines light inside what long, thin (-5[1])communication devices (10[1])used for high-speed Internet? ■END■ (10[3])