A 4×256 Gbps Silicon Transmitter with On-Chip Adaptive Dispersion Compensation

The exponential growth of data traffic propelled by cloud computing, artificial intelligence, and the Internet of Things demands innovative advancements in optical communication technology. Wavelength division multiplexing (WDM) has been instrumental in enhancing transmission rates within high-speed optical modules. However, as single-lane data rates surpass 200 Gbps in O-band transmission, chromatic dispersion in optical fibers emerges as a critical barrier, especially at wavelengths distant from the zero-dispersion point, such as 1271 nm. Here, we present a novel 4-channel silicon photonic transmitter capable of 1 Tbps aggregate data rate, featuring integrated on-chip adaptive dispersion compensation. This transmitter utilizes Mach-Zehnder modulators (MZMs) with adjustable input intensity splitting ratios, enabling precise control over the chirp magnitude and sign of the transmitted signal. By dynamically tuning the input splitting ratio between the MZM branches, we generate chirped signals that effectively counteract fiber dispersion at specific WDM wavelengths. Experimental demonstrations show successful transmission of 4 × 256 Gbps (4 × 200 Gbps) four-level pulse amplitude modulation (PAM-4) signals over 5 km (10 km) of standard single-mode fiber at the high-dispersion wavelength of 1271 nm. The bit error ratios achieved are below the 7% hard-decision forward error correction (HD-FEC) threshold of 3.8 × 10-3, accomplished without resorting to power-intensive pre-emphasis techniques. To the best of our knowledge, this work represents the first demonstration of a silicon-based 1 Tbps transmitter with integrated on-chip adaptive dispersion compensation. Our results highlight a significant leap towards scalable, energy-efficient, and high-capacity optical interconnects, underscoring the potential of this technology in future local area network WDM (LAN-WDM) applications within data centers and high-performance computing systems.