The photonic revolution

The battle between traditional electronics is being fought on two fronts:

• information transmission;

• information processing, in other words, computers.

We are already into the era when information is transmitted by pulses of light rather than through a copper wire. Particles of light - photons - can carry many thousands of times more information than wires. Optical fibres work by trapping light within a solid rod of glass which is surrounded by a cladding material with different optical properties, that is, a lower refractive index, than the core. The difference in refractive index causes light to be bounced off the outer casing with little loss of intensity over a considerable distance. Because of this, rates of transmission of information will increase at an exponential rate. The limiting factor is the speed of light.

Optical fibres can carry up to 25 trillion bits per second. Quite soon the whole world will be linked to an optical fibre superhighway based on photonic materials. One consequence is that teleworking will become much more prevalent, enabling commercial enterprises to scale down their centralised operations. High capacity communication systems based on a multimedia supercorridor accommodating audio, computer and visual communication will have a major impact on work patterns. Already teleconferencing is reducing the need for costly gatherings of executives as companies spread their operations globally. This will offer much greater freedom to employees as regards their place of abode.

It is probable this will lead to a considerable reduction in the need for high concentrations of office accommodation. Towns and cities will compete on the basis of amenity and quality of life since people will have much greater freedom as to where to live. This will be further driven by developments in transport.

The second theatre of war was information processing. At present optical fibres require electronic devices to convert information into optical pulses and, at the receiving end, to decode the information. The goal of current research is to create the photonic integrated circuit, that is, one that is free of electronic mediation. This will herald the next IT revolution when, as Philip Ball puts it:

The photonic integrated circuit which processes light on a chip ... will see computers change qualitatively. Not only will they be faster, but entirely new kinds of computer architecture should become possible. In other words, we will discover new ways to make machines think.'

(Made to Measure, Princeton, 1997 p. 58)

Computers are major consumers of energy not only in use but also because of the heat they generate which often must be disposed of mechanically. The all-photonic computer will be much faster, use a fraction of the energy of an electronic computer and generate virtually no heat. This will make a significant impact on the energy demand of the standard office. It will also have implications for design of the building fabric and the services. Couple this with the introduction of LEDs and it is certainly conceivable that commercial buildings will more than meet their energy demands by means of the next generation of photovoltaic cells. The autonomous office is nigh.

Renewable Energy 101

Renewable Energy 101

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable. The usage of renewable energy sources is very important when considering the sustainability of the existing energy usage of the world. While there is currently an abundance of non-renewable energy sources, such as nuclear fuels, these energy sources are depleting. In addition to being a non-renewable supply, the non-renewable energy sources release emissions into the air, which has an adverse effect on the environment.

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