Laser guns have been a staple of science fiction for over a hundred years, perhaps first seen in the Heat-Ray used by the Martian invaders in H.G. Wells’ The War of The Worlds in 1897. It’s been featured in books, TV, movies, and video games ever since, and is perhaps one of the most identifiable motifs of ‘the future’, alongside flying cars, food in pill form, and the colonisation of other planets.
In terms of futuristic weaponry, in the human imagination there’s nothing more advanced than the laser gun, whether it’s a handheld blaster or a death ray from space capable of blowing up planets.
But how feasible is this technology? And if it is possible to build laser guns, when can we expect to see them?
How Would Laser Guns Work?
The first laser (Light Amplification by Simulated Emission of Radiation) as we know it was invented by Dr Theodore Maiman in 1960. They work through spatial coherence, which allows the light to be focused to a tight point, with all the photons moving in one direction. Moreover, it is also monochromatic, opposed to the light of all wavelengths that comes from normal light sources.
The military has been using lasers to guide certain ordinances like missiles since the Vietnam war. The technology makes up the majority of the guidance suite, which either reads laser light coming from the launch point, or by using on-board sensors to pick up laser light reflected from the target.
To use the lasers themselves as the means of dealing damage requires a an entirely different design of weapon. There are already laser guns that can shoot down drones with High Energy Laser (HEL) systems by melting the chassis.
An anti-personnel laser weapon would most likely work through generating intense heat. The immediate benefit of a laser over a conventional bullet is the speed. A rifle bullet travels at 1,200 metres per second where a laser moves at the speed of light, 186,000 miles per second. However, a laser like this would require massive amounts of power to pack the same amount of kinetic power as a bullet, roughly 30,000 watts. This makes incorporating a battery of sufficient size to generate this amount of power into the body of the weapon an almost impossible task with current technology.
Why We Don’t Have Laser Guns Yet
The battery issue is just one of the reasons why we don’t have laser guns yet. But also there are laws prohibiting the use of lasers to blind enemy combatants. Directly exposing an eye to a laser for even a short space of time can cause permanent damage to vision, or even blindness. So if hand-held laser weapons are ever invented, laws may need to be changed in order to use them.
Another issue is that lasers are far less effective in air than in a vacuum, and this only gets worse in fog or rain. This becomes less of an issue the more powerful the laser is, but this increases the risk of the weapon overheating as it fires.
However, the US Army is planning on utilising laser-based weaponry as early as 2023, calling them ‘directed-energy weapons.’ The UK is likewise working on its own laser project, and China famously claims to already have a laser weapon in active use.
It may only be a matter of time until wars are fought using this laser technology, leaving us farther than ever from those utopian futures imagined so long ago.