快猫短视频

Using plasma to make lasers could make them more powerful and more compact.

and Pierre Michel at Lawrence Livermore National Laboratory in California proposed a laser design that includes components made from plasma, a state of matter similar to a hot 鈥渟oup鈥� of charged particles. They calculated that because plasma can reflect and focus very intense light without being damaged by it, this method could help build lasers thousands of times more powerful than the strongest ones that currently exist.

鈥淲e want lasers that can deliver a lot of light intensity, which allows us to do a lot of new, interesting physics. The problem is that as lasers produce more and more power, they have a tendency to destroy themselves,鈥� says Edwards. 鈥淏ut we can put a lot more light on a plasma without damaging it, anywhere from 100 times to as much as a million times.鈥�

The researchers mathematically modelled a laser where a component called a transmission grating, usually made of glass-like materials such as silica coated in gold, would instead be created by shooting smaller lasers into gas to make a specially patterned plasma. Like conventional lasers, lenses and mirrors would help produce a beam of light, but passing the beam through the plasma grating would turn it into a very quick and intense pulse of light.

The power and size of a laser are determined by the ability of the device鈥檚 components to withstand a beam鈥檚 intensity without breaking, says Edwards.

The most powerful existing lasers require metre-sized transmission gratings and can output tens of petawatts of power over a quadrillionth of a second. If sustained for an hour, this would output more than twice as much energy as the whole US electric grid鈥檚 hourly power usage. Edwards says the plasma lasers could produce equally powerful beams with plasma gratings only 1.5 millimetres in diameter. Using even larger gratings could lead to the creation of unprecedentedly powerful lasers.

at the University of Rochester in New York says that the new design is compelling, but that controlling and confining plasma inside of a device is an engineering challenge. However, he says, the design presents an opportunity to push the frontier of laser power and intensity forward, maybe even as far as being able to 鈥渞ip鈥� empty space into pairs of particles and anti-particles with very intense laser pulses.

Edwards says that though some plasma gratings have been created in experiments, building a whole laser around one will probably take more than a few years. In the short term, the researchers are aiming to test their design by building a smaller but equally powerful version of existing high-intensity lasers.