Team achieves record 1 trillion bits per second speed on single chip
By ANITuesday, March 1, 2011
WASHINGTON - A development team at at Infinera Corp. in Sunnyvale, Calif. Has achieved a record one trillion bits per second (1 Terabit/s) speed on a single integrated indium phosphide chip.
“Traditional transponder-based system architectures are inflexible and costly and time-consuming to upgrade,” said Dr. Radhakrishnan Nagarajan, research fellow at Infinera and a senior member of Infinera’s PIC development team.
“Our PIC approach enables us to make optical networks more powerful, flexible and reliable than ever before using equipment that is significantly smaller, less expensive and uses much less energy.”
Their latest PIC is at the heart of a new 10-channel receiver, each channel operating at 100 Gbit/s data rates - the first in the industry to achieve a capacity of 1 Terabit/s on a single photonic integrated chip.
It contains more than 150 optical components-such as frequency tunable local oscillator (LO) lasers, devices for mixing the LO and incoming signals, variable optical attenuators for LO power control, a spectral demultiplexer to separate the individual wavelength channels, and 40 balanced photodetector (receiver/transmitter) pairs-all integrated onto a chip.
The key technical advance operating behind 100-Gbit/s-per-channel technology is the ability to detect incoming data encoded using the optical industry’s most spectrally efficient modulation technique, called polarization multiplexed Quadrature Phase-Shift Keying, or PM-QPSK.
PM is similar to the wireless communications technique of alternating the polarization of adjacent channels. QPSK modifies the light’s phase to represent the data. Together, PM-QPSK permits four times more information to be conveyed each second than was possible with the previous method, which simply switched the laser light on and off.
“But just as important as a transmitter’s clever and efficient encoding method is a fast and reliable way for the receiver to convert the information back to its original form,” said Nagarajan.
“For PM-QPSK, we designed and integrated narrow-linewidth lasers that detect the phase encoded data very efficiently.”
Infinera expects PICs with a capability of a terabit or more to be commercially available within a few years.
PICs enable massive amounts of cost-effective bandwidth and facilitate the networks at the heart of the Internet to become more scalable and quicker to react to sudden changes in demand.
“In many ways, PIC-based optical networks are starting to take on the intelligent features of routed (IP) networks, like the ability to reroute traffic in the event of a break in the fiber-but at a fraction of the cost and power consumption,” Nagarajan added.
Nagarajan’s presentation at OFC/NFOEC will take place Monday, March 7 at 3:15 p.m. in the Los Angeles Convention Center. (ANI)
