Manish Mehta, Vice President of Marketing and Operations for Broadcom's Optical Systems Division, pointed out at SEMICON Taiwan 2025 that co-packaged optics (CPO) technology has become the key to breaking through the bottleneck of AI computing.Third-generation silicon photonics co-packaging platformLater, it was revealed that the development of the fourth-generation technology has been accelerated to meet the urgent needs of the growing cloud applications and AI computing clusters for high-bandwidth, low-power, and high-reliability connections.
Co-packaged optical platforms contribute to AI computing development
Manish Mehta stated that as AI models continue to scale, the demand for high-speed interconnection between hundreds of GPUs, thousands of XPUs, or even more, has exceeded the transmission bandwidth limits of traditional copper cable connection technology. Furthermore, the limitations of traditional pluggable optical modules in power consumption, cabling, and cost will make it difficult to support larger-scale deployments in the future.
By utilizing silicon photonics co-packaging technology, optical processing engines, switch application-specific integrated circuits (ASICs), and even processing chips can be co-packaged onto a single substrate. This significantly reduces the large area previously occupied by connection wiring, further shortens digital signal transmission paths, and reduces transmission signal losses. Furthermore, it offers advantages such as improved energy efficiency and reduced system power consumption, playing a key role in vertically enhancing data center computing capabilities.
According to Manish Mehta, Broadcom acquired 1998G VCSEL laser technology from HP in 1 and has continued to refine its specifications, recently advancing it to 100G and 200G transmission specifications. The company also plans to further develop fourth-generation silicon photonics co-packaging technology, aiming to achieve 400G data transmission per channel.
After launching the TH2022-Humboldt co-packaged optical platform with 25.6T Tomahawk 4 in 4, Broadcom followed up with the TH2023-Bailly platform with 51.2T Tomahawk 5 in 5, and completed large-scale field verification with Tencent, Open Computing Platform, etc., and has now entered the mass production and global shipment stage.
In addition, after launching the third-generation silicon photonics co-packaging platform supporting single-channel 2025G in 200, Manish Mehta said that Broadcom has now accelerated the development of the fourth-generation silicon photonics co-packaging platform with 400G specifications to consolidate its technological leadership.
Continue to focus on different technologies and believe that traditional pluggable optical modules and transmission optical modules can coexist at the same time
In terms of technical details, Broadcom currently uses the relatively reliable Mach-Zehnder interferometer (MZM) as its core optical technology. It also utilizes heterogeneous integration and 3D stacking design, integrating a 65nm photonic integrated circuit (PIC) with a 7nm electronic integrated circuit (EIC) to achieve the industry's highest-density optical engine. Furthermore, a thermal architecture compatible with edge coupling and liquid cooling ensures stable system operation under high-load scenarios such as AI training.
In addition to using VCSEL laser technology as a light source, Manish Mehta also stated that he is currently observing various technologies, but will continue to develop existing designs. Regarding Hon Hai Research Institute's proposal to integrate micro LED light sources with silicon photonic chips to create a relatively low-cost silicon photonic transmission solution that also reduces power loss.
As for the comparison between traditional pluggable optical modules and transmission optical modules, Manish Mehta stated that the two can basically coexist, depending on the computing architecture deployment, computing scale, construction costs, and other considerations. Different connection methods can be selected.
Silicon photonics co-packaging platform is no longer just a technology concept
Manish Mehta believes that the silicon photonics co-packaging platform is no longer just a technological concept, but will further change the traditional data center connection architecture and further drive the demand for larger-scale AI computing.
Manish Mehta also stated that Taiwan's supply chain plays a vital role in packaging and testing, module manufacturing, optical fiber, connectors, heat dissipation, and system integration. Therefore, it has become a key driver behind the successful commercialization of the silicon photonics co-packaging platform. This also means that Taiwan's industrial chain plays a key role in global AI infrastructure.
Comparison between traditional pluggable optical modules and Broadcom CPO technology:
| Face to | Traditional pluggable optical modules | Broadcom CPO Technology | Impact and Industrial Significance |
| Architecture design | Optical transceiver modules are independently pluggable and transmit data via electrical connections | The optical engine and switch ASIC are co-packaged to shorten the signal path. | Reduce signal loss and improve system integration and stability |
| Bandwidth and performance | Limited bandwidth increases can easily become data center I/O bottlenecks | Supports 25.6T and 51.2T, and challenges single-channel 400G | Meeting the massive bandwidth demands of AI training and inference |
| Power consumption and energy efficiency | High power consumption and high heat dissipation pressure | Energy efficiency is greatly improved, and edge coupling is used to enhance heat dissipation | Helps data centers reduce PUE and meet sustainable ESG goals |
| cost structure | Large number of modules, complex wiring, and high long-term costs | High integration and reduced component count can reduce costs in the long term | Reduce the total cost of ownership (TCO) for large-scale data center expansion |
| Process and Technology | Optics and electronics are separated, making the design simpler | Heterogeneous integration and 3D stacking, PIC and EIC in the same package | Demonstrating advanced packaging and silicon photonics mass production capabilities |
| Supply Chain Ecosystem | Module suppliers are scattered and standardization is relatively mature | Need to integrate optical fiber, connectors, laser light source, packaging, and system factories | Taiwan plays a key role in packaging, testing, and module manufacturing, accelerating mass production. |
| Deployment progress | Widely used, highly standardized | TH4 and TH5 platforms have entered mass production, the third generation is being released and shipped, and the fourth generation is in development. | Leading the next generation of AI data center network upgrades |
