Lasers in the spotlight: "The technologies have huge potential"

When was laser technology invented?

The principle of what is called "stimulated emission" was described as early as 1917 by Albert Einstein. However, the accepted date is 16 May 1960, when engineer Theodore Harold Maiman from Hughes Research Laboratories in Malibu, California, successfully fired the very first laser by using a ruby crystal to concentrate light, producing the characteristic red beam which has been associated with the technology ever since.  

Although nowhere near as powerful as today’s lasers, this first laser beam shone as bright as a million suns, delivering pulses around one millisecond in length. This was the very first time that such a large quantity of light had been propagated in a straight line and focused onto a single point. 

So this is a fairly recent technology, but one in which Thales is a pioneer and leader.

Can you give us some examples that have enabled Thales to position itself as a leader?

Of course. I would mention three examples. 

In 2012, Thales supplied the Berkeley Laboratory in California with a laser accelerator known as BELLA (Berkeley Lab Laser Accelerator). BELLA was the first laser to deliver a petawatt of power – the equivalent of one million billion watts – by focusing all of its energy into a pulse that lasted for around thirty femtoseconds¹. 

Six years later, Gérard Mourou, a long-standing research partner of Thales in the field of power lasers and currently scientific advisor to the President of École Polytechnique, was awarded the Nobel Prize in Physics, along with Donna Strickland, for the invention of a technique known as chirped pulse amplification, which creates ultra-short, very high-intensity laser pulses of around one terawatt. 

The following year, in 2019, an ultra-powerful laser developed by Thales for the Extreme Light Infrastructure for Nuclear Physics (ELI-NP) European research project at Bucharest, Romania, generated its first pulses at a peak power level of 10 petawatts – a world record. Currently the most powerful laser in the world, it will help the scientific community gain a better understanding of the physics of materials. 

These key milestones in the history of lasers show how Europe, and in particular Thales, is leading the way in a technology that really hasn't been around for very long.

Apart from scientific applications, do you have any examples of the use of laser technology in everyday life?

Yes, they are used to mark, cut and weld metals, manufacture semiconductors using laser lithography, scan barcodes in the supermarket and even enhance the display quality of our mobile phones. 

In the medical domain, they are used to treat cancer by means of proton or electron beam therapy. And the “flash” effect – very short, high-intensity pulses which are less harmful to the patient – is also expected to deliver considerable benefits. The same kind of lasers can also be used in X-ray imaging and to produce isotopic tracers for medical scanning applications. 

In industry, laser-based X-rays are used to detect defects in components, in particular small (sub-millimetre) defects in parts with thicknesses of several tens of centimetres, as well as in cargo scanning applications to identify hazardous or illegal substances inside containers. 

But we are still a long way from utilising the full potential of the technology. This is particularly true for very high-power lasers, which can be used to build particle accelerators up to a thousand times smaller than conventional accelerators.

One of the most promising applications of these high-power lasers seems to be in the energy sector

Nuclear fusion indeed offers hopes of delivering clean, safe, waste-free energy, and it is now clear that short-pulse, very high-power lasers will play a key role in future energy plans. 

In August 2021, scientists at the Lawrence Livermore National Laboratory announced a historic achievement in the race to develop nuclear fusion: using the National Ignition Facility’s ultra-high-power laser system, they had created a plasma which yielded more than 1.3 megajoules of energy in one-tenth of a nanosecond. 

And several private companies have been set up recently, aiming to produce inertial fusion energy within the next decade using systems driven by power lasers.

These kinds of power lasers have lots of other applications, such as treating radioactive waste and cleaning up space debris. The technologies have huge potential, but to fully exploit this potential we have to significantly improve the energy efficiency of the high-intensity lasers themselves. This is what we are doing now, for example with the XCAN demonstrator project conceived by Nobel Prize-winner Gérard Mourou at the Ecole polytechnique in partnership with Thales. 

Developing more efficient intense lasers is also be one of the key areas of focus of Heracles3, a joint research partnership between Thales, the French National Centre for Scientific Research (CNRS) and the Institut polytechnique de Paris (IP Paris)2 . Heracles3 will turbocharge Thales’s efforts to make these fascinating new societal applications a reality as quickly as possible. 

1. One femtosecond is equal to one millionth of a billionth of a second.