The 8-channel InP monolithic tunable optical router, or MOTOR, produced by University of California, Santa Barbara, scientists. The left half of the chip holds eight wavelength converter arrays, and the right holds the arrayed waveguide grating router. Credit: University of California, Santa Barbara.
Researchers at the University of California, Santa Barbara have
made a key step towards eliminating
optical-to-electrical-to-optical conversion stages in router
hardware.
UCSB researchers Steve Nicholes and Milan Mašanović have produced
the world's first eight-channel monolithic tunable optical router,
operating error-free at 40 Gbit/s on a single InP/InGaAsP chip.
The 4.25 mm x 14.5 mm device integrates eight tunable wavelength
converters with an arrayed waveguide grating router (AWGR). It
contains over 200 functional elements, including more than 150
on-chip diodes, produced using 14 lithography steps.
The epitaxial structure includes ten compressively-strained quantum
wells, and an undoped InP layer in the passive sections of the
device that reduces absorption losses in its AWGR.Nicholes and
Mašanović produced the chip using a quantum well intermixing
approach to broaden the bandgap of the quantum wells and define the
passive regions. They then deposited p-type InP in a final regrowth
step that buries the AWGR and defines the upper cladding of the
device.
“We are able to use a structure with quantum wells sandwiched in
the center of the waveguide to achieve high-gain semiconductor
optical amplifiers and high-power sampled-grating distributed Bragg
reflectors,” said project leader Daniel Blumenthal.
The team's ultimate goal is to shrink the size of state-of-the-art
internet routers that occupy a full 7-foot equipment rack today
down to a single linecard.
This requires pushing back the boundaries of how many optical
devices can be integrated onto a single chip.
An eight-channel router is an impressive first step but Blumenthal
already has his eye on 64-channel optical routers.
“The key is using 4-inch, and hopefully some day larger, InP or
migrating to the new silicon/InP platforms that are coming out,” he
told compoundsemiconductor.net.
“The larger wafers will be needed to get multiple devices this
size, then of course the yield, ways to test and package, would all
need to be worked out.”
The monolithic tunable optical router, or MOTOR, is a product of a
project called LASOR that Blumenthal is principal investigator for.
Standing for “Label-switched optical router”, LASOR is in turn an
approximately $18 million element of a US Department of
Defense-funded project, called Data in Optical Domain-Network
(DOD-N).
Sponsored by the DARPA Microsystems Technology Office and Army
Research Labs, DOD-N aims to remove the need for any
optical-to-electrical-to-optical conversions, and other
communications system bottlenecks.
The LASOR project has been running since 2004 and is just finishing
its Phase II work, with a 12-month duration Phase III stage already
confirmed.
Richard: 又是UCSB！只不过这次不是Rodwel他们了，是另外一伙变态，来自Optoelectronics Technology Center of UCSB。8通道40Gbps光路由器集成电路，集成了光-电-光转换器。光的东西不是很懂。
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