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" is an acronym for "light amplification by stimulated emission of radiation". The fir ...

source and the

detector A sensor is a device that produces an output signal for the purpose of sensing a physical phenomenon. In the broadest definition, a sensor is a device, module, machine, or subsystem that detects events or changes in its environment and sends ...

.http://www.freepatentsonline.com/3825916.html
accessed 26 Jan 2011 Stronger lasers can be used to injure 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. 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 executive of the European Union (EU). It operates as a cabinet government, with 27 members of the Commission (informally known as "Commissioners") headed by a President. It includes an administrative body o ...

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 or machinery such as that used in agriculture, mining or construction. Most common ...

or repulsor beams and

force fields Force field may refer to: Science * Force field (chemistry), a set of parameter and equations for use in molecular mechanics simulations * Force field (physics), a vector field indicating the forces exerted by one object on another * Force field ( ...

. *'' 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 video game developed by Valve Corporation, Valve for Windows, Mac OS X, Linux, PlayStation 3, and Xbox 360. The digital PC version is distributed online by Valve's Steam (service), Steam service, while al ...

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

Titanfall 2 ''Titanfall 2'' is a first-person shooter video game, developed by Respawn Entertainment and published by Electronic Arts. A sequel to 2014's '' Titanfall'', the game was released worldwide on October 28, 2016, for PlayStation 4, Windows, and ...

'' 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 netting. A fence differs from a wall in not having a solid foundation along its whole length. ...

Video game gameplay Fictional energy weapons