A laser fence or laser wall is a mechanism to detect objects passing the line of sight between the

laser A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word ''laser'' originated as an acronym for light amplification by stimulated emission of radi ...

source and the

detector A sensor is often defined as a device that receives and responds to a signal or stimulus. The stimulus is the quantity, property, or condition that is sensed and converted into electrical signal. In the broadest definition, a sensor is a devi ...

. Stronger lasers can be used to

injure Major trauma is any injury that has the potential to cause prolonged disability or death. There are many causes of major trauma, blunt and penetrating, including falls, motor vehicle collisions, stabbing wounds, and gunshot wounds. Depending ...

entities passing the laser beam. In fiction, laser fences may have the ability to stop intruders by blocking or injuring them.

Description

A laser fence mechanism detects objects passing the line of sight between a

source and

. Stronger lasers can be used to injure entities passing the laser beam, as in a

mosquito laser A mosquito laser is a proposed device that would use lasers to kill mosquitoes. The primary goal would be to reduce malaria infection rates. In 2007, the Bill & Melinda Gates Foundation asked Intellectual Ventures to find a way to fight and even ...

. Fictional uses of laser fences often extend the concept so that fences may have the ability to prevent intruders by blocking or injuring them.

Agricultural usage

Lasers are used to keep birds from eating blueberries by being perceived as a predator. The

European Commission The European Commission (EC) is the primary Executive (government), executive arm of the European Union (EU). It operates as a cabinet government, with a number of European Commissioner, members of the Commission (directorial system, informall ...

is funding research into a laser fence to scare away rats and other pests.

Border fences

The Indian Border Security Force (BSF) has implemented a laser wall system—called LASER Wall—along some parts of its border to stop intrusion.

In fiction

Films

In the 1992 film ''Fortress'', prisoners are kept secured by laser walls. In the 1995 film ''Congo'', a laser fence is used as part of other high-tech equipment to defend a camp against vicious gorillas.

Videogames

Laser walls appear frequently in videogames. The concepts of these fictional fences can be compared to other concepts like

tractor A tractor is an engineering vehicle specifically designed to deliver a high tractive effort (or torque) at slow speeds, for the purposes of hauling a Trailer (vehicle), trailer or machinery such as that used in agriculture, mining or constructio ...

or repulsor beams and

force fields In physics, a force is an influence that can cause an object to change its velocity unless counterbalanced by other forces. In mechanics, force makes ideas like 'pushing' or 'pulling' mathematically precise. Because the magnitude and direction ...

. *'' Deus Ex: Human Revolution'' has laser grids which you can't get past without getting a Remote Hacking augmentation, allowing you to affect it. *'' Monaco: What's Yours Is Mine'' has a hacker class which use viruses to shut down lasers. *''

Portal 2 ''Portal 2'' is a 2011 puzzle-platform game developed by Valve for Windows, macOS, Linux, PlayStation 3, and Xbox 360. The digital PC versions are distributed online by Valve's Steam service, while all retail editions are distributed by Elect ...

'', with laser barriers as obstacles *'' Sly Cooper: Thieves in Time'' *''

Titanfall 2 ''Titanfall 2'' is a 2016 first-person shooter, first-person shooter game developed by Respawn Entertainment and published by Electronic Arts. A sequel to 2014's ''Titanfall (video game), Titanfall'', the game was released worldwide on October ...

'' has laser fields to prevent access to areas. * X-Morph: Defense uses laser fences to kill off enemies.

Notes

{{reflist Fences

Fence A fence is a structure that encloses an area, typically outdoors, and is usually constructed from posts that are connected by boards, wire, rails or net (textile), netting. A fence differs from a wall in not having a solid foundation along its ...

Fictional energy weapons