| 释义 |
absorption The irreversible conversion of some or all of the energy of an electromagnetic wave to another form of energy as a result of its encounter and interaction with matter through which it is propagating or upon which it is incident. Generally, the sum of the electromagnetic energy converts to thermal energy, i.e., heat, which transfers to the matter, and which results in some amount of signal attenuation. An electrical signal propagating through a copper conductor, for example, attenuates as some electromagnetic energy is converted to thermal energy due to the vibration of free electrons in the copper. Similarly, an optical signal propagating through a glass optical fiber (GOF) suffers some attenuation as the photons interact with the crystalline silicon dioxide and dopants that comprise the fiber and convert to thermal energy. Radio waves also suffer considerably from absorption, which in fact is used to advantage in microwave ovens. See also attenuation and propagation. |