METHODS AND APPARATUS FOR ADJUSTING POWER IN AN OPTICAL SIGNAL, FOR PROVIDING A SEAMLESS OPTICAL RING AND FOR PROVIDING A BIDIRECTIONAL EQUALIZED AMPLIFIER

摘要

A method and apparatus for adjusting power in an optical signal are disclos ed and a bidirectional equalized amplifier for providing bidirectional equalization, employing the apparatus and method is disclosed. Use of the method and apparatus to form a seamless ring in an optical network is also disclosed. The method of adjusting power involves splitting an input composite sign al into respective drop signals in separate wavelength bands with a splitter. A n attenuator attenuates the drop signals to produce attenuated drop signals. A combiner combines the attenuated drop signals to produce a first output composite signal in which the power is equalized. The bidirectional equalize d amplifier involves a first apparatus as described above for splitting, attenuating and then combining signals in respective wavelength bands of an input composite optical signal, to produce a first output composite signal. An amplifier amplifies the first output composite signal to produce an amplifie d first output composite signal which is passed through a reverse path in a second apparatus of the type described above to a second input port of the second apparatus, for transmission on an optical medium, while selectively splitting, attenuating and then combining signals in respective wavelength bands of a second input composite optical signal, received at the second inp ut port of the second apparatus to produce a second output composite signal. The second output composite signal is then amplified to produce an amplifi ed second output composite signal which is then passed through a reverse path in the first apparatus to the first input port of the first apparatus for transmission on an optical medium.