Patent ID: 7493042

Claim:
An optical communication system, comprising: a) a plurality of transceiver ports each comprising: a first transmitter configured to produce a downstream multi-longitudinal mode (MLM) spectrum signal, wherein the spectrum of the downstream MLM-spectrum signal comprises a plurality of distinct narrow-spectrum peaks each corresponding to a longitudinal mode; a first temperature controller configured to vary the temperature of the first transmitter to tune the spectrum of the downstream MLM-spectrum signal; and a first receiver configured to receive an upstream spectrum-sliced signal; b) a first wavelength filter, comprising: a plurality of first branching ports each associated with a specific wavelength channel, wherein each of the first branching ports is in connection with a transceiver port and is configured to receive the downstream MLM-spectrum signal from the first transmitter and send the upstream spectrum-sliced signal to the first receiver, wherein the first temperature controller in the transceiver port is configured to lock at least one of the plurality of distinct narrow-spectrum peaks in the spectrum of the downstream MLM-spectrum signal to the specific wavelength channel; and a first common port configured to output a downstream filtered signal in response to the downstream MLM-spectrum signal, wherein the downstream filtered signal comprises at least one longitudinal mode of the downstream MLM-spectrum signal and the spectrum of the downstream filtered signal is located in a wavelength channel specifically associated with the first branching port at which the downstream MLM-spectrum signal is received; and c) a second wavelength filter, comprising: a plurality of second branching ports each associated with a specific wavelength channel, wherein each of the second branching ports is configured to receive an upstream broad-spectrum signal from an optical network unit; and a second common port configured to output the upstream spectrum-sliced signal in response to the upstream broad-spectrum signal, wherein the spectrum of the upstream spectrum-sliced signal is a portion of the upstream broad-spectrum signal and is located in a wavelength channel specifically associated with the second branching port at which the upstream broad-spectrum signal is received, and wherein the second common port is configured to receive the downstream filtered signal from the first wavelength filter and the downstream filtered signal is routed to one of the second branching ports that is specifically associated with the wavelength channel of the downstream filtered signal.