More and more development initiatives focus on light

Dec 28, 2007 08:36 GMT  ·  By

The IT industry has worked hard during the time in order to achieve the fastest hardware in the tiniest space possible. Miniaturization was the key, but times are changing and things cannot be pushed beyond anymore, due to the materials' physical limits. Light is promising to offer what matter cannot; it's just a question of time and patience until it is completely tamed.

Light has played an important role in networking. We have been using optical fiber for some while, and researchers consider it's time to switch to a faster and more secure network architecture, based on the quantum state of light. Communication between computers using the quantum state of light guarantees security, but the information sent via network is encoded delicately, and many times the key is in a single photon. However, photons often get lost, and proper functionality requires every link to be fine-tuned.

The Nanjing University engineers analyzed the scenario where information is first encoded on a quantum dot that sits between two mirrors. When the dot radiates its information, the photon is bounced by the mirrors straight into a fiber optic cable. At the other end, there is a similar quantum dot that absorbs the photon, which concludes the information transfer.

The process is catalyzed by the Rabi frequency, that is determined by the interaction between the quantum dot and the mirrors that confine it. When excited, the quantum dot will emit a photon that will be reflected back and forth between the mirrors. The process is reversible and another quantum dot will engulf the emitted photon.

There are bumps in the road, however, and one of the major obstacles scientists have to overcome is the pulse duration. The pulse frequency is heavily modified as it traverses a fiber optic system and is less likely to be absorbed at the other end. The engineers are working on modifying the shape of the pulses that control the quantum dots, in order to counteract some of the errors induced by the fiber network between the two dots.

There is a long way until pulse networking would become the next optical fiber, but it would play a key role in tomorrow's ultra-high speed networking.