Silicon Integrated Nanophotonics
Development of on-chip optical interconnects for future Exascale computing systems
The ultimate goal of this project is to develop a technology for on-chip integration of ultracompact nanophotonic circuits for manipulating the light signals, similar to the way electrical
signals are manipulated in computer chips. Nanoscale silicon photonics circuits are being
developed to enable the integration of complete optical systems on a monolithic semiconductor
chip that would eventually allow to overcome severe constraints of today’s mostly copper I/O
interconnects.
The current tendency in high performance computing systems is to increase the parallelism in
processing at all levels utilizing multithreads, increasing the number of chips in racks and
blades, as well as increasing the number of cores on a chip. The scaling of overall system
performance that soon might approach Exaflop/s is, however, out of balance with respect to
limited available bandwidth for shuttling ExaBytes of data across the system, between the
racks, chips and cores.
Optics is destined to be utilized in data centers since optical communications can meet the large
bandwidth demands of high-performance computing systems by bringing the immense
advantages of high modulation rates and parallelism of wavelength division multiplexing. As it
already happened in long-haul communications decades ago when optical fibers replaced
copper cables, the copper cables that connect racks in the datacenters are started now to being
replaced by optical fibers. Following the same trend optics can become competitive with copper
at shorter and shorter distances eventually leading to optical on-board and may be even on-chip
communications.
Artist’ concept of 3D silicon processor chip with optical IO layer featuring on-chip
nanophotonic network
This future 3D-integated chip consists of several layers connected with each other with very
dense and small pitch interlayer vias. The lower layer is a processor itself with many hundreds
of individual cores. Memory layer (or layers) are bonded on top to provide fast access to local
caches. On top of the stack is the Photonic layer with many thousands of individual optical
devices (modulators, detectors, switches) as well as analogue electrical circuits (amplifiers,
drivers, latches, etc.). The key role of a photonic layer is not only to provide point-to-point broad
bandwidth optical link between different cores and/or the off-chip traffic, but also to route this
traffic with an array of nanophotonic switches. Hence it is named Intra-chip optical network
(ICON).
Silicon photonics offers high density integration of individual optical components on a single
chip. Strong light confinement enables dramatic scaling of the device area and allows
unprecedented control over optical signals. Silicon nanophotonic devices have immense
capacity for low-loss, high-bandwidth data processing. Fabrication of silicon photonics system in
the complementary metal–oxide–semiconductor (CMOS)-compatible silicon-on-insulator
platform also results in further integration of optical and electrical circuitry. Following the
Moore’s scaling laws in electronics, dense chip-scale integration of optical components can
bring the price and power per a bit of transferred data low enough to enable optical
communications in high performance computing systems.
To meet these stringent requirements and utilize fully all the benefits of optics an innovative
engineering is necessary at all levels starting from the design of individual devices to the overall
architecture of high-performance computing system. Nanoscale silicon photonics circuits that
are being developed within this project are targeted to enable the monolithic integration of
complete optical systems on a semiconductor chip.
http://domino.research.ibm.com/comm/research_projects.nsf/pages/photonics.index.html
Questões:
1.
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4.
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8.
Qual o objetivo máximo do projeto tratado no texto?
Para quê os circuitos em nanoescala estão sendo desenvolvidos?
Segundo o texto, qual a tendência atual dos sistemas computacionais de alta performance?
O que o texto fala sobre a relação entre fibra ótica e cabos de cobre?
O que é a rede ótica intrachip?
O que o texto fala sobre dispositivos nanofotônicos de silicone?
De acordo com o texto, o que é necessário para que se possa usufruir plenamente dessa nova
tecnologia?
Considerando o texto, qual o significado dos termos abaixo?
a. Enable
b. Overcome
c. Constraints
d. Multithreads
e. High modulation rates
f. Replace
g. point-to-point broad bandwidth optical link
h. unprecedented control
i. low-loss, high-bandwidth data processing