April 2014


Tracing the rays

LEDS are replacing traditional light sources because they are cheaper and more energy-efficient, but also because they can be very stylish. The combination of growing numbers of LEDs and increasing demand for better aesthetics has led to a rise in the use of optical modelling software, so that LEDs can be ‘tailor-made’ for specific applications. But, as the hardware evolves, the software needs to catch up and improve its ease-of-use, processing speed, and standardisation.


Collision course avoided

How do you avoid an asteroid colliding with Earth? The answer, according to Dr Richard Fork at the University of Alabama in Huntsville (UAH), USA, might be to redirect it, or more specifically to slow it down, using ultrafast lasers.

In February 2013, a relatively small asteroid entered Earth’s atmosphere and exploded over Chelyabinsk, Russia with a force equivalent to around 500,000 tonnes of TNT. It caused widespread damage and injured more than 1,000 people.


Powering the pulse

Ultrafast science has been an active area of research ever since Ahmed Zewail won the Nobel Prize in Chemistry in 1999 for his work studying chemical reactions using femtosecond spectroscopy. Today, commercial ultrafast amplifiers are available offering millijoule outputs. The large, research-grade laser facilities, however, are able to amplify to hundreds of joules of energy in ultrashort pulses, which requires highly specialised amplification techniques.


Cascade of excitement

In February, a team from the University of Leeds in the UK announced in the journal Electronics Letters that they had produced more than 1W of terahertz radiation from a quantum cascade laser, more than doubling the previous power output.

The widespread application of terahertz radiation has been impeded by problems in making the lasers powerful and compact enough to be useful, but the Leeds result offers hope that these obstacles are now gradually being overcome.


Taking lasers to the movies

The sci-fi blockbuster Gravity was one of the big winners at this year’s Oscars, picking up seven awards including Best Director. The film, which took five years to make, boasts some spectacular visual effects, but how would laser projectors change the viewing experience?

Laser projectors for cinema offer significant image enhancements over traditional xenon lamps, especially for 3D films like Gravity. Laser-based systems offer wider colour gamuts, higher levels of contrast – and, because the laser doesn’t degrade like a lamp, consistently higher brightness.