Segmented silicon MZM for PAM-8 transmissions at 114 Gb/s with binary signaling

Area of Science:

• Photonics
• Optical Communications
• Integrated Optics

Background:

• Generating multilevel optical signals, such as Pulse Amplitude Modulation with 8 levels (PAM-8), typically requires high-bandwidth electronic digital-to-analog converters.
• These electronic components can be a bottleneck in high-speed optical data transmission systems.

Purpose of the Study:

• To experimentally demonstrate Pulse Amplitude Modulation with 8 levels (PAM-8) signal generation using a silicon multi-electrode Mach-Zehnder modulator as an optical digital-to-analog converter.
• To evaluate the performance of this system for high-speed data links.

Main Methods:

• Utilizing binary electrical signals to drive a silicon multi-electrode Mach-Zehnder modulator.
• Employing a back-to-back configuration to measure Bit Error Rate (BER) for signal quality assessment.
• Implementing minimum mean square error (MMSE) equalization for signal processing.

Main Results:

• Successful generation of PAM-8 signals from binary inputs.
• Demonstration of 38 Giga-symbols per second (GBd) PAM-8 transmission below the Forward Error Correction (FEC) threshold.
• Validation of the modulator's performance in a back-to-back setup.

Conclusions:

• Silicon multi-electrode Mach-Zehnder modulators can effectively function as optical digital-to-analog converters for multilevel signal generation.
• Segmented phase shifters in these modulators eliminate the need for high-bandwidth electronic digital-to-analog converters.
• This approach is highly relevant for cost-effective, high-speed short-range optical data links using standard CMOS processes.