The C3PO Project: Colourless and Coolerless Components for low Power Optical Networks

C-3PO aims to overcome the technological barriers related to the development of low-cost reflective photonic components for building high-capacity WDM-PONs. Specifically, using the reflective transceiver and multi-wavelength source concept, the WDM-PON network can be built as follows:

OLT implementation

Downstream transmitter:

• Arrays of reflective transmitters are employed, each serving 40/80/160 users depending on the size of the PON deployed
• The wavelength channel for each PON is provided by the multi-wavelength source acting as the centralized light source

Upstream receiver:

• An array of receivers integrated with an AWG demultiplexer are used for receiving the upstream data channels (one Rx per wavelength)

Upstream optical carriers

• The multi-wavelength source is also employed to supply the ONUs with continuous laser light that is modulated at the user to generate each upstream data channel

ONU implementation

• A reflective colourless and coolerless transmitter is employed for upstream modulation
• A colourless and coolerless receiver is employed for receiving downstream data

The “reflective” rationale of the project can provide unprecedented cost-saving, flexibility and scalability that cannot be offered using conventional components and systems. C-3PO targets a ‘pure’ WDM-PON scheme, but the same component integration approaches could also be exploited in ‘hybrid’ schemes such as WDM/TDMA PONs with the addition of burst-mode optoelectronics and electronics for the upstream channels.