IBM silicon photonics to speed up cloud and ‘big data’ rates

13 May 2015

Big Blue announces "milestone" in integrated silicon optoelectronics at CLEO 2015 conference.

IBM has this week announced “a significant milestone” in its development of silicon photonics technology that will enable rapid data transmission over longer distances in future computing systems.

In March, optics.org reported how IBM researchers had attached silicon photonic chips directly to a processor, promising faster, cheaper and lower energy solution for computing, cloud and data centers.

In the latest statement released on May 12, the company said, “for the first time, IBM engineers have designed and tested a fully integrated wavelength multiplexed silicon photonics chip, which will enable manufacturing of 100 Gb/s optical transceivers. This will allow datacenters to offer greater data rates and bandwidth for cloud computing and ‘big data’ applications.”

Arvind Krishna, senior VP and director of IBM Research, commented, “Making silicon photonics technology ready for widespread commercial use will help the semiconductor industry keep pace with the growing demands in computing power driven by big data and cloud services. Just as fiber optics revolutionized the telecommunications industry by speeding up the flow of data, we are excited about the potential of replacing electric signals with pulses of light.”

The company added that its latest Si-photonics development will enables the integration of different optical components side-by-side with electrical circuits on a single silicon chip using sub-100nm semiconductor technology. These chips use four distinct wavelengths in an optical fiber to carry data around a computing system. The new transceiver can digitally share the equivalent of 63 million tweets or six million images, or download a high-definition digital movie in just two seconds.

IBM’s CMOS Integrated Nano-Photonics Technology is specified to provide a “cost-effective silicon photonics solution” by combining optical and electrical components, as well as structures enabling fiber packaging, on a single silicon chip. The manufacturing process makes use of standard fabrication processes at a silicon chip foundry, making this technology ready for commercialization, the company said.

Transforming datacenters

“Computer hardware components, whether a few centimeters or a few kilometers apart, can seamlessly and efficiently communicate with each other at high speeds using such interconnects, " the IBM statement continued. "This disaggregated and flexible design of datacenters will help reduce the cost of space and energy, while increasing performance and analysis capabilities for users ranging from social media companies to financial services to universities.”

Most of the optical interconnect solutions employed within datacenters as of today are based upon vertical cavity surface emitting laser (VCSEL) technology, where the optical signals are transported via multimode optical fiber. Demands for increased distance and data rate between ports, due to cloud services for example, are driving the development of cost-effective single-mode optical interconnect technologies, which can overcome the bandwidth-distance limitations inherent to multimode VCSEL links.

IBM engineers in New York and Zurich, Switzerland and the IBM Systems Unit have collaborated to demonstrate a reference design targeting datacenter interconnects with a range up to 2km. This particular chip demonstrates transmission and reception of high-speed data using four wavelengths, each operating as an independent 25 Gb/s optical channel. Within a full transceiver design, these four channels can be wavelength-multiplexed on-chip to provide 100 Gb/s aggregate bandwidth over a duplex single-mode fiber, thus minimizing the cost of the installed fiber plant within the datacenter.

Further details are being presented at this week’s 2015 Conference on Lasers and Electro Optics in San Jose, Ca, through May 15, during the invited presentation entitled “Demonstration of error-free operation to 32Gb/s from a CMOS-integrated monolithic nano-photonic transmitter,” by Douglas Gill and others from IBM.

About the Author

Matthew Peach is a contributing editor to optics.org.