Tweezer for atoms and the taming of the laser – what it is and why you need

Today in Stockholm, were named winners of the Nobel prize in 2018 in physics. Winners were American Arthur Ashkin, Frenchman Gerard Moore and canadian Donna Strickland “for fundamental discoveries in the field of laser physics,” reads the statement on the website of the Nobel Committee.

Arthur Ashkin, Donna Strickland and Gerard Moore

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Half of the prize awarded to Arthur Askino, Professor of the famous Bell laboratories, where in the middle of the last century was the invention of the transistor – the building block of modern electronics. Askin awarded for creation of optical tweezers and their application in biological systems. The second half got Moore and Strickland – a method for generating high-intensity ultrashort optical pulses. Moore works in the famous Paris Polytechnic school and at the University of Michigan (USA). Strickland is a Professor at the University of Waterloo (Canada).

Interestingly, the results of the prize in physics is declared not only in Swedish and English. After that, the Chairman of the Committee repeats the wording in German, French and Russian.

What is optical tweezers how does it work?

Eskin invented the so-called optical tweezers system that allows you to take and move microscopic objects like atoms, living cells or viruses, as we move small visible objects using a regular tweezer. These manipulations are carried out using a special way arranged the laser beam. Microparticle, getting into its electrical field, itself becomes charged, however, uneven. As a result, it “sticks” to a particular way of focused laser beam.

Optical tweezers have become a part of laboratory equipment for scientists who work with proteins, DNA, cells and their parts. The simultaneous use of a large number of tweezers, for example, allows to separate the blood cells healthy and the infected (that’s one of the hopes in the fight against malaria).

What is optical pulses and why are they shortened?

Moore and Strickland came up with a way to curb the lasers. In 80 years people have learned to lasers more and more power, but it couldn’t be used – because of the high intensity they turn into plasma everything in its path, including the air and destroyed the system through which.

In 1985 the current nobility figured out how to first stretch the laser, two diffraction gratings, and then collect it two – in vacuum. This method is called amplification of chirped pulses.

As a result, the laser is much more high intensity was gave up very short pulses. So short that imagine it is extremely difficult – femtosecond equals 10-15 seconds, this is one kvadrilliona a fraction of a second. This effectively removed all constraints on laser power systems.

How did it help the people to regain the lost vision?

Such an exotic and difficult to understand objects are actually used not only in science, they can meet in his life an ordinary man. More precisely, they reveal the ordinary person in his life possibilities that were previously totally unrealistic.

Is laser vision correction. Method femtosecond laser vision correction (Small Incision Lenticula Extraction) removes part of the cornea of the human eye and thereby corrects myopia.

The idea of laser correction was proposed in 1960-e years, however, to the works of Moore and Strickland to realize it was impossible: long pulse overheated the eye tissues and damaged them, and the short was too weak to obtain the desired incision in the cornea. Today millions of people around the world operated and returned lost, seemingly irretrievably, vision. The procedure is affordable and painless.

Why ultra-short pulses – the invention of the future?

Ultrashort and powerful laser pulses are used in hundreds of different ways. With their help observe the processes in living matter and chemical reactions very accurately because the pulse is very short and allows you to record even a short-lived intermediate States.

They can be used to cut or “punch” very small holes in very small objects (and again – unimaginably small), driving, thus, the properties of materials.

So, for example, produce a surgical stent. Sam Moore, however, sees his discovery as invention of the future, the main application of which is yet to come: it’s faster electronics, more efficient solar cells, catalysts, new energy sources and more powerful accelerators.

The last – not the whim of the researchers of elementary particles: a powerful but compact accelerators can significantly advance medicine as a form of therapy and diagnostics, first of all, cancer.

Whether Askin offended by the Committee?

Arthur Ashkin became the oldest winner in the history of the award: less than a month ago, he was 96 years old, that is, he was born in 1922. However, apparently, the honorable retirement he never left: in response to a call from the Nobel Committee, he replied that he’s a little busy, because writing a scientific article.

It’s a bit like the reaction of the eccentric former Russian citizen Andrei Geim, who after the news of the Nobel prize for the discovery of graphene in 2010 has not joined in celebrating colleagues and locked in the office, “because it must work”. Eskin may have been offended by the Committee who developed his ideas Steven Chu received the Nobel prize for cooling and retention of atoms using lasers in 1997.

The woman-a physicist – a Nobel laureate?

Donna Strickland young – she ain’t sixty, but she’s a woman. The third woman-Nobelist in the history of the Nobel prize in physics.

The first female laureate in physics was Marie Curie in 1903, became the first woman awarded a Nobel prize at all. Then Maria Goeppert-Mayer received the award in 1963. Work that earned her the award, Strickland performed in graduate school, working under the supervision of Gerard Moore.

Why the winner-the Frenchman worked in Nizhny Novgorod?

One of the laureates of Frenchman Gerard Moore – for several years he worked in Russia in the Lobachevsky University in Nizhny Novgorod. This choice is not accidental: Nizhny Novgorod Institute of applied physics is one of the largest laser centers in Russia. In particular, it is one of two Russian scientific centres participated in the now famous experiment LIGO that has been recorded by the gravitational wave (for this discovery the Nobel prize in physics was awarded last 2017).

Moore has long worked with experts of the center, and in 2010 when a contest was announced so-called “mega-grants” – large grants to attract leading scientists to work at Russian universities, University of Nizhny Novgorod decided to go to Moore, tells his colleague, head of Department of General physics Professor Michael bakunow.

“The grant we received in 2010, it lasted three years, and then was renewed. So there was a Laboratory of extreme light fields, where Gerard had spent four months in the year. We managed to create a unique petawatt laser complex, which continues to work today,” said the bakunow.

Why would a physicist explored the icons?

“Gerard is an eager person with a very wide range of interests, so it not only gave an impetus to the development of laser systems in our city, but started a new interesting application. In particular, we have begun the study of art objects using terahertz radiation can be generated by a laser. This radiation with a wavelength of 300 microns, which is somewhere between light and microwaves. With this radiation, you can look inside opaque objects. Our graduate students traveled to the Louvre to explore the murals, and here we are with Gerard explored the icons.

One of the icons there was a defect on the surface of unknown origin. We researched and helped, therefore, to determine the optimal strategy for restoration and conservation. But one day, Gerard called me from Moscow and said that he in the Cathedral of Vasily the blessed, where the later frescoes and plaster down to find earlier, but it could be done without destruction using terahertz radiation!

Now he develops the idea to destroy space junk with lasers on this subject have already been a conference. He has work eye surgery with a femtosecond laser, they were made in Michigan. Despite his age, Gerard – a man who constantly fantasizes and gives ideas,” continues bakunow.

That has allowed 74-year-old winner to cross the Volga?

As it turned out, cheerfulness, flights, and active in 74 years, not without sport. According to his colleagues, Moore swims every day in the kilometres in the pool or in open water. And once even crossed the Volga below Nizhny Novgorod.

“He’s very available. When he was sitting on the chair, any student could approach him to talk about physics. Although Gerard and then there was the scientific value of world level”, – concluded the scientist.

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