VCSEL-based differential modulation technique for high-speed gigabit passive optical networks

ABSTRACT

With the convergence towards 5G, optical networks need to be upgraded to support the emerging data tsunami. This work experimentally demonstrates the first real-time transmission of 20 Gbps over a class 10G 1550 nm vertical cavity surface emitting laser (VCSEL) in the context of on-off-keying (OOK) modulation format, by employing VCSEL differential drive mode technique, for adoption in high-speed gigabit passive optical networks (GPONs). Two OOK data streams each with 10 Gbps are differentially modulated onto a single VCSEL, therefore generating an aggregated data rate of 20 Gbps OOK signal. A receiver sensitivity of -13.36 dBm is experimentally achieved. Through extinction ratio optimization, an error free transmission over 24.7 km single mode fibre is attained, with a transmission penalty of 1.91 dB. Our proposed technique alleviates band-limitation of the VCSEL carrier, and doubles the channel data rate without replacing the transmitter optics.

KEYWORDS:

• Vertical cavity surface emitting laser
• passive optical network
• on–off-keying
• optical fibre

Additional information

Funding

We are grateful for Research Funding and support from: Telkom, Dartcom, Ingoma, CISCO, DST, CSIR, NLC, NRF, THRIP, ALC and scholarship funding from SKA/NRF.