The Jock That Won a Nobel in Physics
Earlier last month there was a buzz in the science community. The Nobel Prize in Physics for 2018 had three winners sharing the prize. The winners are Arthur Pushkin (who got half of the prize), Gérard Mourou and Donna Strickland who shared the remaining half of the award money equally.
It was worth noting that Donna Strickland, who was not yet a full a full professor because she never applied for it also happened to be the third women to win a Nobel Prize in 55 years after the first, Marie Curie in 1903 and Maria Geoppert-Mayer in 1963.
Donna Strickland. Image credits: By Wikipedia CC BY-SA 4.0 , via Wikimedia Commons from The Optical Society Link]
If you a fan of the science fiction franchise, Star Trek, you may be familiar with the term "tractor beam". However, if you haven't, there is no need to worry. It involves a beam without a tractor. It is a beam that is capable of drawing things into it. Science fiction right? Yes, but of late real scientists are rivalling their science fiction peers in getting the fiction into reality. Remember the 1989 movie Back to the Future hoverboard scene? We are now in that future. Well, let's say that a flying hoverboard is no longer fiction as it might have to be back then as you can now buy a flying hoverboard.
The 59-year old Donna Strickland, the Canadian scientist and now Nobel prize physicist and only living female Nobel laureate in physics, who affectionately referred to herself as a laser jock, in her attempt to make young aspiring scientists see physics as fun, has been working on lasers for more than thirty years. In 1985 she and Gérard Mourou discovered a process of amplifying laser pulse known as the chirped pulse amplification.
A graphic which shows the process of chirped pulse amplification. Image credits: By Wikipedia Public Domain from CVF Link]
The field of laser physics received a facelift due to the work of Mourou and Strickland through the creation of the most powerful pulse of light known to humankind. The laser of the 1960s has one thing in common, which are their lack of intensity and power. However, the defining moment came in 1985 when the out-of-the-box thinking of the duo, Strickland and Mourou opened up an era of more powerful lasers.
Nevertheless, there is a problem which other scientists encountered in the quest for a more intense laser before the new technique of the Strickland and Mourou. The problem is that of damages as a result of shockwaves from the high intense long pulse laser.
The revolutionary method instead of creating a high-intensity laser that invariably destroys the amplifying system, first stretch the pulse. The stretch increases the time which directly reduces the maximum power of the pulse. This technique safely allows the amplifier to amplify the laser significantly without the accompanying damage. After the amplification, the end product is hugely compressed, again in time. That leads to a small area accommodating a large amount of pulse.
The beam-stretching affair may sound easy on paper, but the duo initially had to run a 2.5km long fibre optic cable for the process. After encountering some challenges of not getting any pulse from the other end, they conclude that the optimum length of 1.4km could do just fine. Finally, the first successfully stretching was a success in 1985.
Now the extremely short pulses can be very powerful with the capability of up to petawatts, which is more powerful than a trillion solar panels placed in the sun.
Since such a powerful laser can burn whatever is amplifying it, it is designed to last for a very short duration. Therefore pulses lasting only as a femtosecond or one million of a billionth second is possible. As if that was not short enough, today we can push pulses up to an attosecond or a millionth of a picosecond, i.e. 108 of a second. To show you how fast this attosecond is, the light which we know is super fast travelling 0.3 nanometers in one attosecond. A nanometer is approximately the distance between two atoms in an object.
Why is it important we make fast pulses? Thank you, I'm glad you asked :)
Have you tried to take a picture of a fast moving object before? Chances are the image may go blurry.
A blurred image of a fast-moving bullet train. Image credits: By Pexel under CC0 from Mechthild Link]
The cause is your camera aperture speed is not fast enough to capture the rapidly changing image of the object. To capture such a rapidly moving object requires an equally high-speed camera. If you have a super fast pulse, there are a host of possibilities out there, one of which is making the fastest film camera with applications in the fields of ever-changing microworld of atoms and molecules.
Also, just as tweeted by the Nobel Prize, there is the possibility of having the most precise drills/cuts made in living materials and also facilitate in better eye laser surgery which is in demand of very short pulse which leaves less scarring to adjoining tissues.
Using the same drilling features which is useful in healthcare, the future of more efficient data storage is bright. Very tiny holes can now be possible and created in materials to further boost its storage capacities.
Laser physics is one in which there are hosts of applications such as more effective photovoltaic cells, more advanced catalysts, new energy sources, etc. Little wonder there is a fierce competition and hardworking scientists are looking for the next breakthrough in their research to help in these areas and more.