Advancements in Silicon Photonics - Optical Signal Processing by Silicon Photonics - page 43

4.9 Silicon Photonics Progress in Last Decade
Photonics is becoming progressively more essential in the field of electronics, the
reason being that it keeps itself up-to-date with both the “more-Moore”, in which
the performance is increased when integration and parallelism is increased, and
“beyond-Moore”, which has new computation principles, advancement trends of
electronics. Silicon photonics is the branch which was initiated by Soref in the
1980s [ 26 , 27 ], is a technology that is capable of combining both photonics and
electronics within a single chip in order to get the advantage of both technolo-
gies: In this way, the capability of electronics to perform high computation is com-
bined with advantage of high communication bandwidth of photonics. The major
attraction of silicon photonics is joined with the opportunity of addition of new
functionalities in electronic components, such as wavelength multiplexing, low
propagation losses, immunity to electromagnetic noise, and high bandwidth. The
key strength of this technology is the silicon properties of non-toxicity, low cost,
and very fine ultra-large-scale integrated aka ULSI circuit fabrication technology,
which has the responsibility of the huge success of silicon in the field of elec-
tronics, can be made most useful. Silicon photonics is the field that is very much
promising in the area of research and with the presence of the first commercial
devices which are very useful in wide range of applications in reality [ 28 ].
Silicon is actually an excellent optical material but suffers from the disadvantage
of poor light emitter, the novelty of emission of light from silicon that is porous in
nature, at room temperature in 1990 [ 29 ] gave major push to the research on light
sources based on silicon. Just after that time, the emergence of silicon micropho-
tonics or optoelectronics concept occurred after one another suddenly [ 30 , 31 ]. The
concept of small-sized Silicon-based waveguides was taking its pace; ranges from
more than 100 μ m² usual waveguides that are based on the refractive index contrast
provided by distinct doping levels in the duration of years 1980s to 5 μ m² sizes of
rib waveguides, where index contrast was provided by Si/SiO 2 .
Material like silicon is very ubiquitous in electronic components and other
micro-nanostructures made by man. Increasing significance of academia and
industry has caused advanced processing in silicon processing techniques. These
processing techniques caused utilization of integrated electronic circuit technology
on a vast scale to produce application specific integrated circuits (ASIC), which
are playing most significant part in the electronic industry these days. ASICs are
not the only products of accurate silicon processing techniques and its advan-
tages—also the advantages continue to plethora demonstrations of micro-opto-
electro-mechanical structures (MOEMS) and micro-electro-mechanical structures
(MEMS). These microstructures are capable of adding real time sensing to the
ICs, resulting in the fabrication of some devices like lab-on-chip commercially
for sensing in meteorology and medicine, etc. Currently, some new disciplines
like Bio-MEMS, NEMS also known as nano-electro-mechanical structures,
etc., are being investigated, aiming to diversifying applications, and growing the