Modal bandwidth, in the discipline of
telecommunications
Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than that fe ...
, refers to the maximal signaling rate for a given distance or – the other way around – the maximal distance for a given signaling rate. The signaling rate can typically be measured in
MHz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one he ...
, and the modal bandwidth is the product of bandwidth and distance (typically expressed in MHz·km). For a cable with a certain modal bandwidth, the maximal frequency can be doubled when the distance is halved, and conversely.
The modal bandwidth is derived from the
modal dispersion
Modal dispersion is a distortion mechanism occurring in multimode fibers and other waveguides, in which the signal is spread in time because the propagation velocity of the optical signal is not the same for all modes. Other names for this phenom ...
of the fiber and the spectral linewidth of the laser:
:
Modal bandwidth is sometimes referred to as EMBc.
{{DEFAULTSORT:Modal Bandwidth
Telecommunication theory