OPTICAL ADD/DROP MULTIPLEXER AND OPTICAL NETWORK SIGNAL TRANSMISSION METHOD

The present invention relates to the field of communications technologies, and in particular, to an optical add/drop multiplexer, so that the optical add/drop multiplexer can ensure proper processing of light in two directions. The optical add/drop multiplexer can complete an extraction of a signal in one direction by using one microring resonant cavity and two optical circulators, and if a wavelength of a signal in the other direction is the same as a resonant wavelength of the microring resonant cavity, the signal may reenter an optical network after passing through two microring resonant cavities and one optical circulator, and is not affected. Therefore, proper processing of optical signals in the two directions is ensured, and the optical signals in the two directions do not interfere with each other.