What unit is used to represent cable length in fiber optics?

Cable length in fiber optics is represented in feet (ft) because it corresponds to the physical distance that the fiber optic cable covers. This measurement is essential for understanding how far signals can travel through the fiber before significant losses occur, and it is typically expressed in feet or meters based on regional preferences.

Microns (um) are used to measure the diameter of the fiber core and cladding, which is crucial for defining the type of fiber (single-mode or multi-mode), but they do not convey cable length. Nanometers (nm) are a unit of wavelength measurement, which is relevant for characterizing light sources used in fiber optics and assessing how different light wavelengths propagate through the cable. Decibels (dB) measure signal loss or gain rather than physical lengths, making it unsuitable for expressing cable length. Hence, using feet as the unit for cable length is appropriate as it directly pertains to the practical application of fiber optic installations and assessments.