60th Anniversary of the Laser

26. April 2022.

Exactly 60 years ago, physicists accomplished one of the historical breakthroughs in the development of science and technology. Specifically, the first laser which emitted a beam of light was created on 16 May 1960, which represents a date of particular significance to the Institute of Physics, Belgrade since it has followed up on the laser development since this achievement to this day. On this occasion, the International Day of Light is being marked across the world and during this month it shall be accompanied by events in Serbia. How did the development of lasers occur and how did these instruments turn out to be so important in our times?

In an article from 1917, Albert Einstein mentioned the possibility of light manipulation to create a solid and focused beam. However, this idea was not developed for decades, nor was there interest for such a thing in the scientific community. The possibilities of that idea application were not at first suspected and nor was it expected that the light would change the world, and the laser would be used in multiple fields starting with medicine to communication. 

After the Second World War, the United States of America started investing ever more resources in the laser research not fully comprehending their full potential, but hoping to improve radar accuracy. In 1953, at Columbia University, Charles Townes and his colleagues developed and patented a device he named a maser (microwave amplification by stimulated emission of radiation), and five years later he produced an idea of a gas laser. However, he was not the first who succeeded in building a laser.

Townes’ work inspired many researchers who tried to put his idea into practice, so in their experiments, they were mainly focused on gases as a medium. Still, the race was won by a player who gathered light in a completely different manner. 

An engineer and physicist Theodore Maiman worked in the American company Hughes which produced aircraft and which, during the Cold War, focused on the space flights. Although he had been hired to work on aerospace travel contracts and his supervisors had not put faith in his experiments with light, he managed to persuade them to invest a certain amount in the construction of a modest device which would emit a beam of light through a ruby crystal.

On 16 May 1960, Maiman’s ideas reached the target to which a great number of his colleagues aspired, and his device made him the father of electro-optical industry. In a short amount of time, lasers attracted the attention of both the professional and general public. Many realized that everyone’s life was about to change. Possibly, the most important step toward this conception was the first use of lasers in medical purposes which occurred as early as at the end of 1961 when eye surgery was performed in the USA using this still novel invention. 

The history of the Institute of Physics, Belgrade is closely linked to the history of lasers. The first lasers arrived in this newly founded scientific institution only two years after Maiman’s invention. In 1962, the first two devices (one ruby and the other helium-neon) were brought from Romania by the then director Aleksandar Milojević. These were the first laser-related experiences in the former Yugoslavia. 

Together with his associates, Professor Milojević managed to launch the laser in the same year, and in 1965 he published a paper on the pulsating ruby laser in the Soviet journal Nauka i žiznj. In the 1960s, when lasers were a major media topic around the world, Miodrag Petrović and Stipe Hajduković, along with Professor Milojević, researched them at the Institute of Physics in Belgrade.

In the subsequent decade, researchers from the Institute of Physics, Belgrade published numerous papers on lasers in internationally recognized journals, and one of the most prominent researchers of that time is Academician Nikola Konjević. The tradition of laser research at the Institute of Physics, Belgrade has been on-going to this day, with the Photonics Centre, one of the centres of excellence, being the one researching them.

As a reminder of the significance which lasers and light, in general, have in our everyday life and science of the 21st century, the date when the first laser was successfully constructed represents the International Day of Light. For the third time in a row, this popular campaign is organized by the National Coordinating Committee of Serbia, and one of the partners is the Institute of Physics, Belgrade, an institution which pioneered laser research in this region.