After a decade of research, conversion of electrical signals to light for high speed transmission is edging into production
Luxtera takes a similar approach, aiming to bring optical speeds closer to the circuit board for high speed data communication by leveraging the existing IC infrastructure—particularly recent developments in stacked-chip packaging—as much as possible. The company says it has shipped more than half a million of its optics-and-transistors-on-silicon devices to date, primarily for active optical cables in data centers. It sees demand for >10M units a year by 2016.
"The silicon infrastructure's development of 2.5D heterogeneous integration is a key technology path forward for photonics," says Chris Bergey, vice president of marketing at Luxtera. "Instead of putting the high value ASIC on a blank silicon interposer with vias and interconnects, we can put the photonics on the interposer and connect it directly to the upstairs die. This allows the silicon to have optical I/O with much lower system power consumption, terabits of speed and >100 meters of reach."
Luxtera has been actively working on building up a silicon photonics ecosystem, licensing its process to OpSiS and STMicroelectronics to offer foundry services and further development, working with Tokyo Electron to develop a test tool, and working with packaging and assembly houses to develop an automated assembly process.
"The silicon photonics IC design and simulation environment is virtually the same as used in contemporary IC design, using the same software tools, but expanded for photonics," notes Peter De Dobbelaere, vice president of engineering at Luxtera. The optical waveguides, modulators, and receivers are manufactured on silicon with CMOS processes that can be compatible with any fab. Then these optical die or wafers can integrated with electronics by advanced IC packaging.