Silicon Photonics - Opportunities and Challenges

Silicon is the principal material used in semiconductor manufacturing today because it is plentiful, inexpensive, and well understood by the semiconductor industry. Silicon photonics is a term given to the science of optical communications, a science that is now looking to do what has been done with so many other electronic devices; make them smaller, faster, and cheaper; specifically, to bypass current barriers in optical communications by integrating optical computing with semiconductor chips.
Silicon photonics aims to provide in- expensive silicon building blocks that can be integrated to produce optical products that solve real communication problems for consumers.

Silicon is an especially useful material for photonics components because it is transparent at the infrared Wavelengths at which optical communication systems operate. Silicon photonic devices can be made using existing semiconductor fabrication techniques, and because silicon was already used as the substrate for most integrated circuits, it was possible to create hybrid devices in which the optical and electronic components were integrated onto a single microchip.

Fiber-optic communication is the process of transporting data at high speeds on a glass fiber using light.

However, this technology is an expensive solution.

The components are typically fabricated using exotic materials that are expensive to manufacture. The trouble with multi-core processor's is an other challenge.

Programming multi-core processors is a complex process at the same time it is quite tough to implement. Here the main goal was to develop high-volume, low-cost optical components using standard CMOS processing the same manufacturing process used for microprocessors and semiconductor devices. Moreover, manufacturing silicon components in high volume to the specifications needed by optical communications was comparatively inexpensive. Fiber is already being used to shuttle data from computers to data storage devices and from computer to computer.
With a huge potential in the optical domain and problems starting in the gigabit range for metal wire circuits, a bottleneck becomes evident. Silicon Photonics showed promise as the answer. The idea was to build all the components for optical circuits with the CMOS manufacturing processes and eliminate the bottleneck.

Extend the optical communication path inside the computer, inside any electronic devices in the path, perhaps even all the way into the microprocessor and memory chips themselves.

Silicon's key drawback was that it cannot release laser light.

However, silicon can be used to manipulate the light emitted by in expensive lasers so as to provide light that has characteristics similar to more-expensive devices.

This was just one way in which silicon can lower the cost of photonics Essential components for the development of silicon photonics: • An inexpensive light source • Devices that can route, split, and direct light on the silicon chip • A modulator to encode or modulate data into the optical signal • A photo detector to convert the optical signal back into electrical bits • Low-cost, high-volume assembly methods • Supporting electronics for intelligence and photonics control The key challenges that were met in the development of silicon photonics are: • Light source.
• Silicon waveguide.

• Silicon modulators.
• Photo detector Applications: Silicon photonics has its wide range of applications in • Optical communication.

• Data com and telecom applications.

• VOA's.
• ROADM's. • Silicon Triplexer.

• Ring resonators.

• Optical shifter /mirror.

• Optical multi channel separating filter.

• Modulated Raman laser. • Raman amplifier. • Wavelength converters.
• Splitters and couplers. • Attenuators This article is an overview of the silicon photonics and its application areas, the current state of device technology, and the challenges that lie ahead on the path to commercial success.
Silicon photonics is on the verge of becoming a viable technology for various applications especially in communication and internet. Already, commercial components such as optical transceivers are available based on the technology.

"Economic" and "heat" compatibility with silicon microelectronics are the main challenges ahead.