The 2018 Physics Nobel prize has been awarded to three incredible physicists in the field of laser physics. Half the prize goes to Professor Arthur Ashkin for his invention of optical tweezers and its application in biology. The other half goes to Professor Donna Strickland and Professor Gerard Mourou for their breakthrough in generating high-intensity ultra-short optical pulses, which led to powerful and precise lasers.
These scientists have truly revolutionized laser physics and its applications. Over the last six decades, laser – originally LASER, an acronym for Light Amplification by Stimulated Emission of Radiation – went from being a borderline science fiction idea to commonly used in everyday aspects of society, from supermarket scanners to high precision surgery.
Ashkin's work focused on using light beams to move objects. Just like tractor beams from many alien-abduction movies, lasers can be used to trap and move tiny objects. This light trap became known as an optical tweezer. They are incredibly useful, particularly in biology, where they have been employed in examining and manipulating cells, bacteria, and viruses. The light doesn’t damage them and so has allowed for unprecedented exploration. Optical tweezers can turn, and push and pull things, and researchers use it daily to study DNA and proteins.
Strickland and Mourou’s work is just as long-lasting and impactful as Ashkin's. The first functioning laser was operated by Theodore Maiman in 1960. Despite immediate improvements, the intensity that could be achieved began to plateau over the following 25 years. Laser appeared to have almost insurmountable limitations.
In her doctoral thesis, Strickland developed with Mourou a technique called the chirped pulse amplification. As she describes, you take a short laser pulse and stretch it, which reduces its intensity. You then amplify the stretched pulse again and compress it. By compressing it you are also increasing the intensity dramatically. Suddenly, your laser's original limitation fades away.
Thanks to Strickland and Mourou’s technique, laser have gotten more and more powerful as well as more and more precise. The applications for this are everywhere – for example, safe laser eye surgery would not be possible without the chirped pulse amplification – and fundamental for our way of life.
Strickland is only the third woman to win a Nobel prize in Physics, after Marie Curie in 1903 and Maria Goeppert-Mayer in 1963.
“We need to celebrate women physicists because we’re out there, and hopefully in time, it’ll start to move forward at a faster rate," Strickland said in the press conference. " I’m honored to be one of those women.”