Breakthroughs in Light Research

It’s almost too hard to believe, but I’ve heard network engineers suggest that we may soon exhaust the bandwidth capacity our busiest backbone fiber routes, particularly in the northeast. At the rate that our use of data is growing, we will outgrow the total capacity of existing fibers unless we develop faster lasers or build new fiber. The natural inclination is to build more fiber – but at the rate our data is growing, we would consume the capacity of new fibers almost as quickly as they are built. Lately scientists have been working on the problem and there have been a lot of breakthroughs in working with light in ways that can enhance laser communications.

Twisted Light. Dr. Haoran and a team at the RMIT School of Science on Melbourne, Australia have developed a nanophotonic device that lets them read twisted light. Scientists have found ways to bend light into spirals in a state known as orbital angular momentum (OAM). The twisted nature of the light beams presents the opportunity to encode data significantly more data than straight-path laser beams due to the convoluted configuration of the light beam. However, until now nobody has been able to read more than a tiny segment of the twisted light.

The team has developed a nano-detector that that separate the twisted light states into a continuous order, enabling them to both code and decode using a wider range of the OAM light beam. The reliever is made of readily available materials and that should make it inexpensive and scalable for industrial production. The team at RMIT believes with refinement that the detector could bring about more than a 100-times increase in the amount of data that could be carried on one fiber. The nature of the detector also should enable it to receive quantum data from the quickly emerging field of quantum computing.

Laser Bursts Generate Electricity. A team led by Ignacio Franco at the University of Rochester along with a team from the University of Hong King have discovered how to use lasers to generate electricity directly inside chips. They are using a glass thread that is a thousand times thinner than a human hair. If they hit this thread with a short laser burst of one millionth of one billionth of a second they’ve found that for a brief moment the glass acts like a metal and generates an electric current.

One of the biggest limitations on silicon computer chips is moving signal into the chip quickly. With this technique an electrical pulse can be created directly inside of the chip where and when it’s needed, meaning a several magnitude improvement in the speed of getting signals to chip components. The direction and magnitude of the current created can be controlled by varying the shape of the laser beam, by changing its phase. This also could lead to the development of tiny chips operating just above the size of simple molecules.

Infrared Computer Chips. Teams of scientists a the University of Regensburg, in Germany and the University of Michigan have discovered how to use infrared lasers to shift electrons between two states pf angular momentum on a thin sheet of semiconductor material. Flipping between the two electron states creates the classic 1 and 0 needed for computing, at the electron level. Ordinary electrons operate in the gigahertz range, meaning there is a limit of about 1 billion interfaces with electrons possible for a device in a second. Being able to directly change the state of an electron could speed this up as much as a million times.

The scientists think it is possible to build a ‘lightwave’ computer that would have a million-times faster time clock than today’s fastest chips. The next challenge is to develop the train of lasers that can product the desired flips between the two states as needed. This process could also unleash quantum computing. The biggest current drawback of quantum computing is that the qubits – the output of a quantum computation – don’t last very long. A much faster time clock could easily work inside of the quantum time frames.

Breaking the Normal Rules of Light.

Scientists at the National Physics Laboratory in England have developed a technique that changes the fundamental nature of light. Light generally moves through the world as a wave. The scientists created a device they are calling an optical ring resonator. They bend light into continuous rings, and as the light in the rings interact that create unique patters that differ significantly from normal light. The light loses its vertical polarization (the wave peak) and begins moving in ellipses. The scientists hope that by manipulating light they will be able to develop new designs for atomic clocks and quantum computers.

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