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 (-5[1])of these devices corresponds to their numerical aperture. Dispersion limits the maximum length of the multi-mode (-5[1])types of these waveguides, (-5[1])which have a higher ratio of core to cladding diameter than their single-mode type. For 10 points, total internal reflection (10[1])confines light inside (10[1])what long, thin (10[3])communication devices used for high-speed Internet? ■END■ (10[1])