The most powerful laser beam ever created has been recently fired at Osaka University in Japan, where the Laser for Fast Ignition Experiments (LFEX) has been boosted to produce a beam with a peak power of 2,000 trillion watts – two petawatts – for an incredibly short duration, approximately a trillionth of a second or one picosecond.
Values this large are difficult to grasp, but we can think of it as a billion times more powerful than a typical stadium floodlight or as the overall power of all of the sun’s solar energy that falls on London. Imagine focusing all that solar power onto a surface as wide as a human hair for the duration of a trillionth of a second: that’s essentially the LFEX laser.
LFEX is only one of a series of ultra-high power lasers that are being built across the world, ranging from the gigantic 192-beam National Ignition Facility in California, to the CoReLS laser in South Korea, and the Vulcan laser at the Rutherford Appleton Laboratory outside Oxford, UK, to mention but a few.
There are other projects in design stages – of which the most ambitious is probably the Extreme Light Infrastructure, an international collaboration based in Eastern Europe devoted to building a laser 10 times more powerful even than the LFEX.
So what is driving scientists all over the world to build these jewels of optical and electronic technology? What is enough to convince politicians to allocate such significant research funds to back these enormous projects?
Recreating the early universe
Well, the first reason that comes to mind is because the “wow factor” that is associated with lasers. But there’s a whole lot more than just exciting scientists’ and enthusiasts’ imagination.
Lasers this powerful are the only means we have to recreate the extreme environments found in space, such as in the atmosphere of stars – including our Sun – or in the core of giant planets such as Jupiter. When these ultra-powerful lasers are fired at ordinary matter it is instantaneously vaporised, leading to an extremely hot and dense ionised gas, which scientists call a plasma. This extreme state of matter is extremely rare on Earth, but very common in space – almost 99% of ordinary matter in the universe is believed to be in a plasma state.
Ultra-powerful lasers allow us to create a small replica of these extreme states and objects from the universe in such a way that they can be studied in a controlled manner in the laboratory. In a way, they allow us to travel back in time, since they can recreate the conditions found in the early universe, moments after the Big Bang. These extremely dense and hot environments, which only ultra-powerful lasers can create, have already taught us a lot about the evolution of our universe and its current state. read more
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