Patent ID: 7068940

Claim:
An add multiplexer comprising: an input port; an optical circulator comprising a first port, a second port, and a third port, said first port of said optical circulator coupled to said input port; an optical monitor mechanism coupled to said third port of said optical circulator; a wavelength add mechanism having an input port X that is connected to said second port of said optical circulator, an input port Y and an output port Z, which wavelength add mechanism is adapted to direct substantially all of a signal's optical power that is applied to input port Y flowing out of its output port Z, leaving an errant signal fraction of said optical power flowing out of said input port Y; a tunable signal source interposed between said input port Y and said optical monitor mechanism thereby providing a feedback path that allows said errant signal fraction of said optical power flowing out of said input port X to influence the signal is applied to input port Y; and an output port coupled to said output port Z.