This report will present an expression for the mechanical behavior of a drum-wound dual coated fiber and an analytical expression for the microbending loss in single mode dual coated fibers. These analytical expressions are then compared with experimental drumwinding microbending loss results to determine their validity.

The bandwidth of the single-mode fiber is derived for both the amplitude-modulation and the heterodyne-detection (AM) system and the intensity-modulation and the intensity-detection (IM) system, in case that the spectral width of the light source is much less than the modulation bandwidth. In the wavelength-division-multiplexing system, the bandwidth per carrier wave is given as a function of the wavelength, and also at the zero-dispersion wavelength. In case of IM system, the frequency dispersion of the fiber causes the harmonic distortion of the signal and reduces the bandwidth to about a third of that in case of AM system.