The new technology, called CMOS Integrated Silicon Nanophotonics, integrates electrical and optical modules on a single piece of silicon, allowing electrical signals created at the transistor level to be converted into pulses of light that allow chips to communicate at faster speeds, said Will Green, silicon photonics research scientist at IBM.
The technology could lead to massive advances in the power of supercomputers, according to IBM. Today’s fastest supercomputers top out at around 2 petaflops, or two thousand trillion calculations per second.
The photonics technology could boost that to a million trillion calculations per second, or an exaflop, helping IBM to achieve its goal of building an exascale computer by 2020, Green said.
“In an exascale system, interconnects have to be able to push exabytes per second across the network,” Green said. “This is an interesting milestone for system builders [who are] looking at building … exascale systems in 10 years.”
Multiple photonics modules could be integrated onto a single substrate or on a motherboard, Green said. Newer supercomputers already use optical technology for chips to communicate, but mostly at the rack level and mostly over a single wavelength. IBM’s breakthrough will enable optical communication simultaneously at multiple wavelengths, he said.
The technology can be manufactured on a standard chip production line and needs no special tools, making it cost-effective, according to IBM. The current demonstration used a 130-nanometer CMOS manufacturing node, but IBM will pursue integration into “deeply scaled sub-100-nanometer CMOS processes,” Green said.
The technology aims to replace the copper wires widely used today for data transfer between chips. Optics can be faster for distances of a few centimeters to a few miles, and consumes less power.
IBM hopes to eventually use optics for on-chip communication between transistors as well. “There is a vision for the chip level, but that is not what we are claiming today,” Green said.
Intel is also researching silicon nanophotonics technology at the silicon level, but has not yet demonstrated the integration of photonics with electronics, according to Green.
IBM’s nanophotonics breakthrough comes after a decade of work in this area at its labs worldwide. Beyond high-performance computing, the company sees the technology being used in other areas such as networking.
“The nice thing about it is we have a platform which allows us to address many different places simultaneously,” Green said.