silicon chip with superimposed currency symbols

[Image: Phil Saunders]

A January 2018 report from the French market research firm Yole Développement concludes that silicon photonics technology, especially in the optical-transceiver market, stands at the threshold of substantial growth, driven in particular by data center demand.

According to the report, “Silicon Photonics 2018,” written by Eric Mounier and Jean-Louis Malinge, silicon photonics technology has “reached its tipping point,” with economies of scale likely to bring down costs and with steady improvement expected in integration, power consumption and reliability. Further, the report notes that an increasing number of players, including both start-up companies and giant firms such as Intel, are becoming established in the industry, joining long-standing silicon-photonics firms such as Luxtera and Acacia Inc.

As a result, the report projects, the market for silicon photonics could mushroom by the middle of the next decade. The study projects a total silicon photonic market value of some US$560 million at the chip level, and nearly US$4 billion at the transceiver level, by 2025—compared with estimated die-level sales of only around US$30 million in 2016.

Huge data flows

Driving that significant growth, according to the Yole report, will be the demands of data centers coping with increasingly massive demands in an ever more bandwidth-hungry online environment—particularly the huge flows of information that take place within the data center itself. The study’s authors note that big internet firms such as Google, Facebook and Amazon are already developing new optical data center technologies, in partnership with firms such as Intel. They also point to increasing activity by Chinese internet giants such as Baidu, Alibaba and Tencent, with plans for new “hyperscale” data centers to be constructed in 2018 that will rest substantially on optical technologies.

“Silicon-photonics technology,” according to a press release accompanying the report, could “grow from a few percent of total optical transceiver market value in 2016 to 35 percent of the market in 2025, mostly for intra-data center communication.” Beyond the data center, the Yole report envisions applications for silicon photonics in other areas, such as high-performance computing, telecom, lidar and biomedical sensing, that could drive demand as well.

Challenges to overcome

Mounier and Malinge see the increasing involvement of “large integrated-circuit foundries,” such as Global Foundries and TSMC, with silicon photonics as a “very encouraging” sign for the business. Yet the report also calls out a number of challenges that silicon photonics technology still needs to overcome.

One is the lack of silicon laser sources, which complicates the integration and requires the use of third-party suppliers of laser sources such as VCSELs. The industry also needs smaller, more efficient modulators, needs to improve alignment, packaging and wafer-scale testing, and will need to address supply-chain issues.

Still another challenge lies in manufacturing, and in bringing silicon photonics on stream with a “zero-change” approach that can manufacture the optical components without requiring any alterations to existing CMOS processes. Refining the zero-change approach, however, could, according to the authors, enable “future inter-chip optical interconnects that could represent huge market volumes.”