Slow light makes photons for faster quantum comms

Scientists have found a way of slowing light down using silicon crystals. The breakthrough has potential to speed up computation, and lead to fundamentally more secure communications, the researchers claim.

By slowing the light down, the scientists make it possible to generate individual photons in a much smaller device. The researchers at the Australian CUDOS program in Quantum Integrated Photonics, along with other scientists in the UK and France, have generated pairs of photons in a device just 100nm across – the thickness of a human hair. Their academic competitors use devices 100 times larger.

Because it is so small, potentially hundreds of these devices could be built into a single chip, the researchers say. This is a key step to building practical quantum technologies that will make communications much more secure and computations many times faster, per the announcement.

Macquarie University's associate professor Michael Steel, explains: "Current systems use classical light to carry information, which hackers can easily tap into and use to their advantage. But you cannot copy the information encoded in quantum states without being noticed by the system. Single photon devices will ensure communication and information systems are secure from hackers, guaranteeing peace of mind for the users."

The work is described in a paper to be presented at CLEO 2011, a conference devoted to laser science and quantum electronics, in Baltimore next week.