Research

"It is lighted neither by window nor by lamp, yet is filled with a soft radiance." This is part of the opening paragraph to E. M. Forster's short story The Machine Stops, in which he describes a small room where the walls themselves glow and light the room. Now, 100 years after its publication, this concept is becoming a reality.

Researchers at the Risø National Laboratory for Sustainable Energy at the Technical University of Denmark, have demonstrated for the first time the use of a wind turbine equipped with a laser for improved performance^†.

Light is good for your health. Most notably, there are significant health benefits from vitamin D, which is produced in our bodies by the absorption into the skin of ultraviolet (UV) radiation. There are also dietary sources of vitamin D, but one of the best and most enjoyable involves simply sitting back and soaking up the sun's rays.

We've previously reported on the use of light patterning techniques to manipulate the movement of particles in solution (Microscopic particle manipulation for screening operations), but now the method has been improved upon and we can see it in action.

The demand for consumer electronics to get smaller, lighter and cheaper, is a stimulus for great ingenuity. Cell phones are a classic example where electrical engineers and designers are constantly working to put a whole lot more into ever smaller spaces. And now that cameras are almost as standard a feature in these devices as the ring tone, optical engineers must also devise increasingly clever ways to shrink the optics while improving their performance.

Lasers which can control the movement of particles are still confined to the microscopic world, but if you have an over-reactive imagination, you might wonder just what the limits are on the size of bodies which these devices can control and whether science fiction's tractor beams are becoming a reality. Today's technology may not be capable of producing force fields that lock on to starships and guide them in to land, but the size of particles which can be manipulated by light are getting larger.

Researchers in the US have come up with a way of improving the sensitivity of metal-semiconductor-metal (MSM) photodetectors without compromising their performance in terms of speed. They accomplished this by modifying the area around the detector to produce a plasmonic lens, which enables it to detect more of the incoming light^1,2.

If you want to squeeze more electricity from your solar cells, try keeping them clean for a start. The Mars rovers, Spirit and Opportunity, know all about that: their power is significantly diminished when layers of dust build up on their solar panels, which can only be removed by a fortuitous gust of wind. Here on Earth we have the advantage of rain and dew, which can facilitate the removal of dirt and dust, allowing more light to be absorbed and converted into electricity.

There was a time when nature dictated the behaviour of light, making sure it followed a few simple rules which clever people like Newton and Fraunhoufer came to understand, enabling them to take control of light with such marvels as the reflecting telescope and the diffraction grating. The clever people of today, however, are turning those well established rules on their heads and manipulating light in ways never before seen in nature. The future is one of super lenses and invisibility cloaks, all made possible by meta-materials, and these complex materials could soon be far easier to make.

While I was leafing through the news stories of the past week, looking for something big in the world of optics, I received a press release about something really big: the world's largest laser is now complete. Read on for the full press release from Lawrence Livermore National Laboratory.