Multiple input detection and digital signal processing for uncooled ONUs in a TWDM-PON with a commercial WDM demultiplexer

• A simple uplink transmission scheme with multiple-input direct detection is proposed for TWDM-PONs.
• The proposed scheme allows temperature drift of lasers at the uncooled ONUs.
• Successful delivery of 10-Gb/s optical NRZ signals with ±0.4-nm wavelength drift is achieved experimentally.
• Simulation analysis is also given to discuss methods improving power budget.

A simple uplink transmission scheme with multiple-input direct detection and digital signal processing has been proposed and experimentally demonstrated for the time and wavelength division multiplexed passive optical networks (TWDM-PONs), to allow wavelength drift of lasers at the uncooled optical network units (ONUs). In our experiment, after passing by the commercial 100-GHz WDM demultiplexer, three 10-Gb/s NRZ signals with minimum signal wavelength separation of 50-GHz can be recovered successfully after 50-km standard single-mode fiber (SSMF) transmission. Simulation results are also obtained to analysis the receiver sensitivity at different wavelength separations and discuss methods improving power budget.