A breakthrough in opto-electronics detectors by Intel promises to address the
shortage of network bandwidth which some believe could lead to the collapse of
the internet. The system could also improve inter-chip and on-chip
communications.
A
paper
published in Nature Photonics details the performance of an Avalanche Photo
Detector (APD) based on silicon rather than the normally used indium phosphide.
Intel's research team created a sensor for light detection and amplification
using silicon and Complementary Metal-Oxide Semiconductor processing to give a
"gain-bandwidth product" of 340GHz, which they claim is the "best result ever
measured for this key APD performance metric".
'Gain' is an electronic system's ability to increase the signal power of the
device, and Intel claims that its research could "lower the cost of optical
links running at data rates of 40Gbit/s or higher" and "proves for the first
time that a silicon photonics device can exceed the performance of a device made
with traditional, more expensive optical materials such as indium phosphide".
"The gain [multiplied by] the bandwidth is a fixed number," said Dr Mario
Paniccia, of Intel's
Photonics
Technology Lab, explaining the significance of a 'gain-bandwidth product'.
"Commercial APDs made with indium phosphide have a typical gain bandwidth of
120GHz. For use in 10Gbit/s long-haul communications links, typical APDs would
cost $200 to $300 [£134 to £202].
"Because of the high gain bandwidth we're achieving here in a low-cost
device, we can produce a device that gives better performance at 10Gbit/s, and
can also operate better at 20Gbit/s and 40Gbit/s and higher."
Dr Paniccia added that, depending on the application, Intel could adapt the
device to focus on speed, distance or power savings.
"We can reduce the laser power, but still get the same gain as current APDs,
" he said. "The potential applications of the new APD range from communications
interconnects to quantum cryptography, biochips and eventually chip-to-chip and
on-chip interconnects."
Questioned about commercialisation of the product, Paniccia admitted that
Intel still has to optimise the device for performance and increase its
sensitivity. "We are working to drive this aggressively into our platforms and
also looking at the reliability of these systems," he said.
Dr Paniccia explained that optics would evolve in the next five to seven
years, but that it will be difficult to replace copper at distances of under six
inches for chip-to-chip interconnects.
"Predicting something five years ahead - an eternity in this industry - would
be difficult," he said. "On-chip interconnects are still quite a way out. Ten
plus years."
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