Coupled microlasers could act as logic elements
1 min read
Following computer simulations, researchers at the Vienna University of Technology have created a system of two coupled lasers which behave in a counterintuitive fashion: additional energy can switch it off, whilst a reduction of energy may switch it on. In this way, says the team, logical circuits might be built using light.
Working with Princeton University's engineering faculty, the Vienna researchers used quantum cascade lasers emitting at terahertz frequencies, with a diameter of less than 0.1mm. They found that when lasers were coupled, the balance of energy gain and loss led to intriguing physical effects.
"Usually, there is a simple relationship between the amount of energy pumped into a laser and the brightness of the beam emitted by it", said Professor Stefan Rotter. "If the energy supply is too small, nothing happens. Once a critical threshold is reached, the laser starts to emit light and the more energy, the brighter the laser beam."
The researchers believe laser coupling can lead to new electro optical switches, with optical elements being used to process information. As they can easily fit on a chip, the team concluded, coupled microlasers would be ideal candidates.
