This document summarizes information on advancements in optical fiber through silicon photonics. It provides background on optical fibers and their construction. It then discusses advantages of optical fibers such as high bandwidth and small size. Silicon photonics is introduced as using lasers to transmit data between computer chips faster than electrical conductors. Key advantages of silicon photonics are discussed, such as higher data transfer speeds. The document outlines Intel's work developing silicon photonics chips to address growing bandwidth needs in data centers. Finally, it discusses the progress and future potential of silicon photonics technology.

1. A SEMINAR REPORT ON
“ADVANCEMENT IN
OPTICAL FIBER
THROUGH SILICON
PHOTONICS”

2. CONTENT
 An introduction to optical fiber
 Optical fiber construction
 A general system for optical fiber communication
 Advantages of optical fiber
 Silicon photonics in a nutshell
 Siliconize photonics
 Advantages of silicon photonics
 Intel’s work on silicon photonics
 Past and present of silicon photonics

3. An Introduction to Optical Fiber
 An optical fiber or optical fibre is a flexible, transparent fiber made by drawing glass
(silica) or plastic to a diameter slightly thicker than that of a human hair. Optical fibers are
used most often as a means to transmit light between the two ends of the fiber and find wide
usage in fiber-optic communications, where they permit transmission over longer
distances and at higher bandwidths (data rates) than wire cables.

5. A general system for optical fiber
communication

6. Advantages of optical fiber
(a) Enormous potential bandwidth :The optical carrier frequency in the range 1013 to 1016 Hz (generally in
the near infrared around 1014 Hz or 105 GHz) yields a far greater potential transmission bandwidth than
metallic cable systems (i.e. coaxial cable bandwidth typically around 20 MHz over distances up to a
maximum of 10 km) or even millimeter wave radio systems (i.e. systems currently operating with
modulation bandwidths of 700 MHz over a few hundreds of meters). Indeed, by the year 2000 the typical
bandwidth multiplied by length product for an optical fiber link incorporating fiber amplifiers (see Section
10.4) was 5000 GHz km in comparison with the typical bandwidth–length product for coaxial cable of
around 100 MHz km.
(b) Small size and weight: Optical fibers have very small diameters which are often no greater than the
diameter of a human hair. Hence, even when such fibers are covered with protective coatings they are far
smaller and much lighter than corresponding copper cables. This is a tremendous boon towards the
alleviation of duct congestion in cities, as well as allowing for an expansion of signal transmission within
mobiles such as aircraft, satellites and even ships.
(c) (c) Electrical isolation:Optical fibers which are fabricated from glass, or sometimes a plastic polymer, are
electrical insulators and therefore, unlike their metallic counterparts, they do not exhibit earth loop and
interface problems.
(d) Immunity to interference and crosstalk:Optical fibers form a dielectric waveguide and are therefore free
from electromagnetic interference (EMI), radio-frequency interference (RFI), or switching transients
giving electromagnetic pulses (EMPs). Hence the operation of an optical fiber communication system is
unaffected by transmission through an electrically noisy environment and the fiber cable requires no
shielding from EMI.
(e) Signal security:The light from optical fibers does not radiate significantly and therefore they provide a
high degree of signal security. Unlike the situation with copper cables, a transmitted optical signal cannot
be obtained from a fiber in a noninvasive manner (i.e. without drawing optical power from the fiber).

7. (f) Low transmission loss: The development of optical fibers over the last 20 years has resulted in the
production of optical fiber cables which exhibit very low attenuation or transmission loss in comparison
with the best copper conductors.
(g) Ruggedness and flexibility: Although protective coatings are essential, optical fibers may be manufactured
with very high tensile strengths. Perhaps surprisingly for a glassy substance, the fibers may also be bent to
quite small radii or twisted without damage.
(h) System reliability and ease of maintenance: These features primarily stem from the low-loss property of
optical fiber cables which reduces the requirement for intermediate repeaters or line amplifiers to boost the
transmitted signal strength
(i) Potential low cost: The glass which generally provides the optical fiber transmission medium is made
from sand – not a scarce resource. So, in comparison with copper conductors, optical fibers offer the
potential for low-cost line communication.

8. Silicon photonics in a nutshell
 Silicon photonics is an evolving technology in which data is transferred among
computer chips by optical rays (laser light), which can carry far more data in less
time than electrical conductors can. The optical fiber is directly built into
semiconductor chips to give IT “computing at the speed of light”.
 Silicon photonics is the study and application of photonic systems which
use silicon as an optical medium. The silicon is usually patterned with sub-
micrometre precision, into microphotonic components. These operate in the infrared,
most commonly at the 1.55 micrometre wavelength used by most fiber optic
telecommunication systems. The silicon typically lies on top of a layer of silica in
what (by analogy with a similar construction in microelectronics) is known as silicon
on insulator (SOI).

10. ADVANTAGES OF SILICON PHOTONICS
 Traditional copper cabling is stifling datacenter evolution and high-performance
computing (HPC) because of its slow data transfer capacity. Silicon photonics –
which uses optical fiber for data transfers – increases bandwidth in servers and
racks, improves data transfer speeds and reduces datacenter complexity.
 Standard copper-based Ethernet networking is inadequate for HPC applications,
datacentres or for managing growing data volumes efficiently, and IT is struggling to
provide faster systems with more effective bandwidth and, hopefully, at lower cost to
end users.
 In a TEDTalk documentary on YouTube, Intel fellow Mario Paniccia (pictured) says:
“If you had the capability of transferring data at 50Gbps between two devices, you
are talking about transferring an HD movie in less than a second.”
 As SiPh develops further, it can realise data transfer at 1Tbps in a cost-effective way.
“That means you can transfer or download a whole season of HD TV from one device
to another in less than a second,” says Paniccia. “It will allow us to keep up
withMoore’s Law and we will not be limited by internal network speeds.”
 Silicon photonics is also capable of feeding a number of parallel optical data streams
into a single fibre, which will reduce datacenter cabling problems.

11.  Silicon photonics devices far exceed the capabilities of copper cabling by offering
data rates of about 100Gbps and so are are better suited for HPC applications and
datacentres.
 Excitement has been created around products and devices based on SiPh, partly as
the telecom and data communication segments are moving to 100Gps interconnects.
 Its compatibility with well-known and mature CMOS fabrication technology offers
advantages, such as low-cost, high-volume and reliable manufacturing with
nanoscale precision. Applications can typically be found in telecommunication and
data-communication, sensing and advanced instrumentation.
 Integration with CMOS-based electronics allows for adding the driver and control
electronics on the same chip, greatly reducing packaging complexity and cost. Vice-
versa the addition of a photonic layer and interconnects hold the promise of solving
speed bottlenecks in future computing and chip platforms.

16. INTEL’S work on silicon photonics

17. Computer chips connected through
optical fiber

18.  Intel is set to launch silicon photonics chips later this year as it
moves the technology from research to the production phase.
There is huge bandwidth growth across multiple markets,
including datacenters, HPC, telcos and consumer electronics.
 Such data explosion requires innovative technologies. Intel
silicon photonics offers opportunity for cost-efficiency,
increasing as volume grows.
 In 2011, Intel co-funded a silicon photonics research and
production centre at the University of Washington.
 The technology will allow new capabilities and flexibility to
address the growing needs of datacenters.

22. PAST, PRESENT AND FUTURE OF SILIOCN
PHOTONICS
 The pace of the development of silicon photonics has quickened since 2004 due to investment by industry
and government. Commercial state-of-the-art CMOS silicon-on-insulator (SOI) foundries are now being
utilized in a crucial test of 1.55-mum monolithic optoelectronic (OE) integration, a test sponsored by the
Defense Advanced Research Projects Agency (DARPA).
 The preliminary results indicate that the silicon photonics are truly CMOS compatible. R&D groups have
now developed 10-100-Gb/s electro-optic modulators, ultrafast Ge-on-Si photodetectors, efficient fiber-to-
waveguide couplers, and Si Raman lasers.
 The new paradigm for the Si-based photonic and optoelectric integrated circuits is that these chip-scale
networks, when suitably designed, will operate at a wavelength anywhere within the broad spectral range
of 1.2-100 mum, with cryocooling needed in some cases

23. Refrences
 Optical Fiber Communications: Principles and Practice (3rd Edition)- John.M.Senior
 IEEE Journal of Selected Topics in Quantum Electronics ( Volume: 12, Issue: 6, Nov.-dec.
2006 )
 IEEE Journal of Selected Topics in Quantum Electronics ( Volume: 12, Issue: 6, Nov.-dec.
2006 )
 IEEE Communications Magazine ( Volume: 50, Issue: 2, February 2012 )
 www.intel.com/content/www/us/en/architecture-and-technology/silicon-photonics/silicon-
photonics-overview.html