Net-400-Gbps PS-PAM transmission using integrated AMUX-MZM

Area of Science:

• Optical Communications
• Data Center Networking
• High-Speed Signal Transmission

Background:

• Datacenter networks require simple, high-speed optical transmission technologies.
• Existing solutions face challenges in achieving high data rates over extended distances with compact components.

Purpose of the Study:

• To demonstrate a simple single-carrier intensity-modulated direct-detection (IMDD) transmission system.
• To achieve a net data rate of 400 Gbps over 20 km using a compact transmitter subassembly.

Main Methods:

• Utilized a compact transmitter subassembly with a 2:1 analog multiplexer (AMUX) and an InP Mach-Zehnder modulator (MZM).
• Employed 162-Gbaud single-carrier probabilistically shaped pulsed amplitude modulation (PS-PAM) driven by a super-digital-to-analog converter (super-DAC).
• Applied digital nonlinear pre-distortion and PS-PAM symbol distribution truncation to enhance signal integrity.

Main Results:

• Achieved a net data rate of 400 Gbps (516.7 Gbps gross) over 20 km.
• Obtained normalized generalized mutual information (NGMI) exceeding the soft-decision forward error correction (SD-FEC) threshold of 0.857.
• Demonstrated the feasibility of a compact transmitter subassembly for high-speed IMDD.

Conclusions:

• This study presents the first net-400-Gbps single-carrier IMDD transmission using a compact transmitter subassembly.
• The developed technology offers a promising solution for future intra- and inter-datacenter networks.
• The combination of PS-PAM, advanced DACs, and pre-distortion techniques enables high-performance optical links.