Lasers are all around us. From barcode scanners to printers to DVD players, they have become an essential part of everyday life. And they are also playing an important part in cutting-edge scientific research.
In particular, an associate professor at the American University of Sharjah, Dr Ali Al Naser, is researching ways of using lasers that could have application in everything from cancer diagnosis and treatment to the generation of oil industry products.
What is especially notable about Dr Al Naser’s work, which has recently been published in the prestigious journal Nature Communications as well as other publications including the New Journal of Physics, is the way in which he and his colleagues have been able to use ultra-short pulses of laser light to break particular bonds within molecules.
It works by targeting the tiny particles, electrons, that encircle the nuclei of the atoms that make up molecules.
The nuclei contain positively charged protons and uncharged neutrons, while the electrons, travelling at incredibly high speed in a “cloud” around the nuclei, are negatively charged and create the bonds that link atoms together.
To target these fast-moving electrons, the laser pulses must be incredibly short, lasting just a handful of what are called femtoseconds (one femtosecond is one millionth of a nanosecond, which is itself a mere one billionth of a second).
“You focus lots of energy on a very tiny space – maybe 1/100th of your hair thickness,” says Dr Al Naser. “The intensity of this focused laser is enough to rip off electrons from their atoms.
“Since these electrons in these clouds move so fast around the nuclei, you need [something] that is short in time that is able to attack them.
“You send a pulse; this lasts just a couple of femtoseconds. Within this time, your target doesn’t have much time to move.”
When electrons are ripped off, bonds between atoms are broken, changing the chemical composition of the molecules.
Many researchers have used lasers to induce chemical changes in substances. What characterises Dr Al Naser’s work – which he has undertaken with colleagues in Germany, Saudi Arabia and the US – is the very specific way these chemical changes have been manipulated: by varying the shape, length, frequency and intensity of the laser pulses, the researchers can determine which bonds are broken.
“Different shapes give you different outcomes. One shape may allow you to break the bond on the left; another shape may allow you to break the bond on the right, or the upper bond or the lower bond,” he said.
“I don’t like to exaggerate, but it’s like you’re changing the DNA of the matter. When you can control which bonds to break, you’re playing with the genetic map of the matter.”
The potential applications, he suggests, are “really, really vast”.
For example, they could be used to improve cancer treatments that employ nanoparticles, a key area of research for increasing survival rates.
Patients are treated with the nanoparticles, which selectively attach themselves to the cancer cells. When a laser is shone on the patient, the nanoparticles are heated, killing the cancer cells without causing “collateral damage” to the healthy cells.
There are also potential uses in diagnosing cancer. For example, the way in which a person’s breath absorbs lasers could be used to indicate whether they have lung cancer.
When it comes to the oil industry, myriad hydrocarbon products could be generated and waste products turned into something useful.
This happens by removing hydrogen atoms attached to carbon atoms, with adjustments to the laser changing which hydrogen atoms are targeted.
Dr Al Naser cautions that it is for now not clear whether the technique could work on an industrial scale.
“The only way to answer this is to do the experiments and see. The idea is new. We don’t know if it will work … I’m optimistic. I don’t see any reason why not.”
But there are stumbling blocks. Dr Al Naser’s work requires specialised and often highly expensive equipment – of a kind that the Arab world still doesn’t have. So while Dr Al Naser plans his experiments from Sharjah, the work itself is carried out at the Max Planck Institute of Quantum Optics in Germany. He has also carried out experimental work in laboratories in the United States and Canada.
He estimates that a facility equipped for world-class research would cost in the region of €10 million (Dh47.6m). Once completed, it would be self-sustaining because, as well as attracting funding from non-commercial research organisations, it could also develop collaborative projects with industry.
“It may seem costly, but it’s not costly compared to other expenses in other sectors,” he said. “It will bring many advances [in] what these lasers can do with matter.
“It would be like a scientific hub in Asia, not only in the Middle East and Arab world.”
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