Wavelength division multiplexed passive optical network

An optical network unit (ONU), comprising:

• a port that receives a first optical signal and outputs a second optical signal;
• an optical coupler having first and second inputs and first and second outputs, the first and second outputs of the optical coupler supplying first and second mixed optical signals;
• a local oscillator laser supplying first and second optical outputs, each of which having a wavelength, the first optical signal being supplied to the first input of the optical coupler and the first optical output of the local oscillator laser being supplied to the second input of the optical coupler;
• a photodetector circuit configured to receive the first and second mixed optical signals and supply electrical signals in response thereto;
• a control circuit configured to supply a control signal in response to the electrical signals, the wavelength of the first and second optical outputs of the local oscillator laser being adjusted in response to the control signal;
• and
• a modulator receiving the second optical output of the local oscillator laser, the modulator receiving a data signal and the second optical output of the local oscillator laser, an output of the modulator being the second optical signal.

An optical network unit (ONU), comprising:

• a port that receives a first optical signal and outputs a second optical signal;
• a tap having an input and first and second outputs, the tap receiving the first optical signal, the first output of the tap supplying a first portion of the first optical signal, the second output of the tap supplying a second portion of the first optical signal;
• an optical receiver circuit configured to receive the first portion of the first optical signal;
• an optical amplifier configured to receive the second portion of the first optical signal, the optical amplifier supplying an amplified optical signal in response to the second portion of said one of the of the first plurality of optical signals;
• an injection locked laser receiving the amplified optical signal and supplying an injection locked optical output;
• and
• a modulator configured to receive the injection lock optical output and supply a modulated optical output in response thereto, the modulated optical output being the second optical signal.

An optical network unit (ONU), comprising:

• a port that receives a first optical signal and outputs a second optical signal;
• a tap having an input and first and second outputs, the tap receiving the first optical signal, the first output of the tap supplying a first portion of the first optical signal, the second output of the tap supplying a second portion of the first optical signal;
• an optical receiver circuit configured to receive the first portion of the first optical signal;
• an optical amplifier configured to receive the second portion of the first optical signal, the optical amplifier supplying an amplified optical signal in response to the second portion of said one of the of the first plurality of optical signals;
• and
• an injection locked laser receiving the amplified optical signal, the injection locked laser being directly modulated in accordance with a data stream, and supplying a modulated injection locked optical output as the second optical signal.

An optical network unit (ONU), comprising:

• a port that receives the first optical signal and outputs a second optical signal;
• a tap having an input and first and second outputs, the tap receiving the first optical signal, the first output of the tap supplying a first portion of the first optical signal, the second output of the tap supplying a second portion of the first optical signal;
• an optical receiver circuit configured to receive the first portion of the first optical signal;
• an optical amplifier configured to receive the second portion of the first optical signal, the optical amplifier supplying an amplified optical signal in response to the second portion of said one of the of the first plurality of optical signals;
• and
• a modulator configured to modulate at least a portion of the amplified optical signal to provide the second optical signal,
• wherein the second portion of the first optical signal includes a first radio frequency (RF) subcarrier, the first optical signal being modulated in accordance with a sideband modulation format such that the first RF subcarrier carries a first data stream, and the second optical signal includes a second RF subcarrier different than the first RF subcarrier, the modulator modulating said one of the plurality of second optical signals such that the second RF subcarrier carries a second data stream.

An optical network unit (ONU), comprising:

• a port that receives a first optical signal and outputs a second optical signal;
• a tap having an input and first and second outputs, the tap receiving the first optical signal, the first output of the tap supplying a first portion of the first optical signal, the second output of the tap supplying a second portion of the first optical signal;
• an optical receiver circuit configured to receive the first portion of the first optical signal;
• a semiconductor optical amplifier configured to receive the second portion of the first optical signal, the optical amplifier supplying the second optical signal in response to the second portion of said one of the of the first plurality of optical signals,
• wherein the second portion of the first optical signal includes a first radio frequency (RF) subcarrier, the first optical signal being modulated in accordance with a sideband modulation format such that the first RF subcarrier carries a first data stream, and the second optical signal includes a second RF subcarrier different than the first RF subcarrier, the semiconductor optical amplifier being directly modulated so that the second RF subcarrier carries a second data stream.