Micro-light

UK technology designed to make complex optical circuits viable for mass-market production will ramp up to full-scale commercialisation within two years.

Southampton University spin-out Mesophotonics has developed technology that can route, bend and process light at the sub-millimetre scale, enabling optics and electronics to be integrated on tiny, cost-effective microchips for use in areas such as lasers, data storage and quantum computing.

The company will move from the development to the production phase after securing more than £5m worth of funding from an international consortium of heavyweight investors.

John Lincoln, the company’s business development director, claimed the technology has the potential to have the same impact on optical circuits ‘as the transistor did on electronics when it superseded the valve’.

Optical circuits currently need to be much larger than their electronic cousins. By shrinking their scale to the sub-millimetre level, it would be possible to integrate optics and electronics on to standard silicon wafers.

‘The designer could then choose the optical or electronics domain, depending on what is the appropriate technology,’ said Lincoln.

Volume manufacturing of devices incorporating the technology could take place using the existing silicon wafer production infrastructure, he added.

Mesophotonics’ technology is based on research into the properties of photonic crystals.

Photonic crystals are created when a periodic modulation of refractive index in a material causes photons to be localised in discrete energy states giving rise to a photonic band structure.

The band structure is analogous to the electronic band structure of semiconductor materials but is created using man-made periodic structures rather than natural crystal structures. The company can therefore use patterns that do no occur in nature and fabricate these in user friendly materials such as silicon.

By changing the pattern, size and shape of the holes in a photonic crystal, devices can be made that perform a wide variety of optical functions. As only the hole pattern needs to be changed to modify the function, multiple functions can be simply integrated onto one device.

Mesophotonics uses silicon substrates to support its photonic crystal waveguide circuits. The optical waveguides themselves are fabricated using technology found in any silicon foundry; this not only allows the company to be ‘fabless’, but also provides it with the route to a large number of potential suppliers.

The UK company has already received its first orders and is in discussions with potential partners over the launch of specific products. It expects devices incorporating its technology to begin appearing on the market over the next two years, said Lincoln. One of the most promising early markets could be supplying chips for emerging optical storage and projection technologies that use red and blue lasers, he added.

Mesophotonics was formed in 2001 to commercialise research into photonic crystals underway since the mid-1990s in three departments at Southampton University.

Its initial backer, high-tech venture specialist BTG, has been joined by three further major investors with a track record of supporting promising emerging technologies. They are Quester of the UK, French venture capitalist Auriga and NIF Ventures, the $1bn (£0.5bn) Japanese investment group.

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