In recent years, the landscape of computing and data transmission has been transformed by the relentless advances in artificial intelligence (AI), machine learning (ML), and high-performance computing (HPC) workloads. These domains are pushing traditional electrical input/output (I/O) systems to their absolute limits, primarily concerning three critical metrics: signal reach, energy efficiency, and bandwidth density. As these demands grow increasingly intense, the need for superior I/O solutions has evolved optics from a mere preference to a fundamental necessity in modern technology. This shift emphasizes the importance of integrating optical components into existing electronic systems to meet increasing throughput and efficiency requirements.
Silicon photonics stands as a frontrunner in this optical integration movement. Leveraging complementary metal–oxide–semiconductor (CMOS) technology, silicon photonics offers an innovative path forward by facilitating the use of established photonic building blocks in high-volume manufacturing. The combination of silicon’s manufacturability and photonic functionalities enables the production of advanced optical devices that could revolutionize data communication. From enhancing bandwidth capabilities to reducing energy consumption, silicon photonics proposes a comprehensive solution to the escalating challenges posed by contemporary computing demands.
There has been remarkable progress in developing critical optical devices necessary for effective silicon photonic integration. On-chip lasers, semiconductor optical amplifiers, and compact modulators are all vital components that drive the performance of optical data links. Additionally, advancements in high-speed photodetectors, low-loss routing techniques, and efficient chip–fiber couplers have augmented the feasibility of deploying these optical technologies in practical applications. Moreover, these devices must exhibit not only high performance but also compatibility with existing electronics, underscoring the importance of synergistic design and engineering.
The recent review of silicon photonics showcases how the integration of these technologies is facilitating a significant reduction in total link energy. Targeting a total energy use that approaches the sub-picojoule per bit range, researchers are working tirelessly to optimize various device aspects. This ambitious goal is not only reshaping the efficiency of data transmission but also paving the way for innovative architectures that can handle the unprecedented bandwidth requirements posed by modern data centers and communications networks.
Key advancements in multimaterial integration techniques, such as hybrid assembly and heterogeneous wafer bonding, are enabling the creation of more complex photonic systems. These methods allow for the combination of different materials and technologies, leading to previously unattainable performance outcomes. Microtransfer printing and monolithic epitaxy are additional techniques in the toolkit of researchers seeking to elevate silicon photonics to new performance heights, expanding its applicability across numerous fields, including telecommunications, data center operations, and even quantum computing.
Co-design of electronics and photonics is another critical area garnering attention. The integration of digital signal processing, serializer/deserializer architectures, and stacked-driver topologies contributes to improved communication fidelity in high-speed networks. Innovations in bias control and thermal tuning mechanisms are equally important, as they ensure that the optical systems operate efficiently under varying conditions, adhering to strict operational requirements of modern electronic environments while minimizing energy losses.
As the demand for higher bandwidth and lower latency continues to surge, system architectures are evolving. The trend is shifting away from traditional pluggable connections toward more refined configurations, such as linear-drive pluggables and co-packaged optic systems. These new architectures promise significant advantages, including reduced footprint and improved thermal management, which are paramount for the efficient operation of densely packed data centers. With the integration of optics occurring closer to the processing units, the prospects for latencies are dramatically improved, aligning with the expectations of next-generation applications reliant on swift data access.
Despite the strides made in silicon photonics, near-term bottlenecks still exist. Thermal pathways pose a significant challenge, limiting performance and efficiency in high-density applications. Moreover, manufacturing yield remains a critical area where further enhancements are required to ensure that advanced optical devices can be produced consistently and at scale. Addressing these issues will be essential for unlocking the full potential of silicon photonics, enabling the field to meet burgeoning industry demands.
Looking toward the future, certain technologies hold the promise of unlocking new dimensions of performance in silicon photonics. On-chip comb sources facilitating dense wavelength-division multiplexing represent a particularly exciting area of advancement. These sources will enable multiple channels of data to be transmitted simultaneously over a single optical fiber, vastly increasing overall throughput. Additionally, wafer-scale 3D electronic and photonic stacks stand to further enhance the integration of optical technologies with electronic systems, creating systems that are not only more powerful but also significantly more energy efficient.
The implications of integrating silicon photonics with current technologies extend beyond mere data transmission. The potential impact is profound, influencing areas such as optical compute I/O and sensing technology, which are pivotal in a variety of applications ranging from computational science to autonomous systems. Furthermore, the growth of quantum photonics, which seeks to leverage quantum mechanics for enhanced data processing and transmission, will benefit from the foundational work being laid by silicon photonics advancements.
In conclusion, the marriage of silicon photonics with CMOS technologies heralds a new era in computing and communication systems. As researchers and engineers continue to push the boundaries of what is possible, the synergy between optics and electronics promises to deliver unprecedented performance and efficiency. This ongoing journey underscores the critical relationship between device-level innovations and systemic improvements, ultimately reshaping our approach to the complexities of an interconnected digital world.
As silicon photonics continues to evolve, it will inevitably chart the course for future advancements across a wide array of domains. With collective efforts focused on overcoming present challenges, the community is poised to witness remarkable breakthroughs that link device-level innovation to expansive system-level performance gains. The future is bright for silicon photonics, signaling not only a technological transformation but also a significant uplift in the capabilities of computing and communications.
Subject of Research: Silicon Photonics and CMOS Integration
Article Title: Integrating silicon photonics with complementary metal–oxide–semiconductor technologies
Article References:
Wan, Y., He, W., Jaussi, J. et al. Integrating silicon photonics with complementary metal–oxide–semiconductor technologies. Nat Rev Electr Eng (2025). https://doi.org/10.1038/s44287-025-00223-0
Image Credits: AI Generated
DOI: 10.1038/s44287-025-00223-0
Keywords: Silicon photonics, CMOS technologies, optical devices, data transmission, thermal management, energy efficiency, multimaterial integration, wavelength-division multiplexing, electronic co-design, quantum photonics.
