Broadcom Inc. today debuted two new chips, the Sian3 and Sian2M, that data center operators can use to power their optical networks.

Optical networks are often used to link together the servers in artificial intelligence clusters. According to Broadcom, its new chips will make such clusters more power-efficient and scalable.

Before a piece of data can be transmitted over an optical network, it has to be turned into light. After arriving at its destination, the light must be turned back into electrical signals that servers can process. The task of turning light into electricity and vice versa is performed by devices called pluggable transceivers that data center operators attach to their network switches.

Broadcom’s new Sian3 and Sian2M chips are designed to power pluggable transceivers. According to the company, the chips can manage up to 1.6 terabits of data traffic per second. Broadcom is also promising better-power efficiency than previous-generation silicon.

The Sian3, the more advanced of the two chips, is based on a three-nanometer manufacturing process. It’s designed for use in transceivers that power SMF fiber-optic cables. SMF is a long-range networking technology that can transmit data between systems located upwards of miles apart.

Inside a data center, SMF can be used to quickly transmit information between servers deployed in different sections of the facility. The technology also lends itself to shuttling traffic between data centers. Broadcom says that the Sian3 can process SMF connections with 20% better power efficiency than earlier silicon.

The second new chip that the company debuted today, the Sian2M, is designed to power network links based on MMF technology. Whereas SMF is geared towards long-range connections, MMF is used to power short fiber-optic cables. The latter technology lends itself to tasks such as linking together AI servers that are located immediately next to one another.

Under the hood, SMF and MMF transmit data in different ways. An SMF-powered fiber-optic cable includes a single strand of glass that supports one wavelength. An MMF cable, in contrast, contains multiple strands of glass that can process light beams with several different wavelengths. MMF-based equipment generally takes up more space and costs less.

The MMF-based Sian2M is based on five-nanometer manufacturing technology. According to Broadcom, there’s a built-in VCSEL laser emitter for generating the light beams that carry data inside fiber-optic cables. It removes the need for transceiver manufacturers to add a standalone laser to their products, which can simplify the hardware development process.

Broadcom says that the Sian2M also shares several features with the three-nanometer Sian3.

Both chips include a retimer module. The more time a piece of data spends traveling over a fiber-optic network, the more likely it is that errors will emerge in the file. Retimer modules can intercept the data and replace it with an fresh, error-free copy to reduce the risk of technical issues.

To further boost network reliability, both of Broadcom’s new chips support an error correction technology called FEC. It works by sending a given piece of data to its destination not one but several times. If one of the data copies contains an error, the rest can still be used to perform processing.

“Our new 3nm Sian3 delivers over 20% power reduction for 1.6T optical modules, while Sian2M with integrated VCSEL drivers and 200G VCSELs brings cost and power efficiency to short-reach links,” said Vijay Janapaty, vice president and general manager of Broadcom’s Physical Layer Products Division.

Broadcom is currently sampling the Sian3 and Sian2M to early customers. 

Photo: Broadcom