Laser fence

A laser fence or laser wall is a mechanism to detect objects passing the line of sight between the laser source and the detector.^[1][2] Stronger lasers can be used to injure entities passing the laser beam.^[3] 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 laser source and detector.^[1] Stronger lasers can be used to injure entities passing the laser beam, as in a mosquito laser.^[3] Fictional uses of laser fences often extend the concept so that fences may have the ability to prevent intruders by blocking or injuring them.^{[4][5][6][7][8]}

Agricultural usage

Lasers are used to keep birds from eating blueberries by being perceived as a predator.^[9] The European Commission is funding research into a laser fence to scare away rats and other pests.^[10][11][12]

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.^[13]

In fiction

Films

In the 1992 film Fortress, prisoners are kept secured by laser walls.^[4] In the 1995 film Congo, a laser fence is used as part of other high-tech equipment to defend a camp against vicious gorillas.^[14]

Videogames

Laser walls appear frequently in videogames.^[15][16][17] The concepts of these fictional fences can be compared to other concepts like tractor or repulsor beams and force fields.

• Deus Ex: Human Revolution has laser grids which you can't get past without getting a Remote Hacking augmentation, allowing you to affect it.^[5]
• Monaco: What's Yours Is Mine has a hacker class which use viruses to shut down lasers.^[6]
• Portal 2, with laser barriers as obstacles^[18]
• Sly Cooper: Thieves in Time^[7]
• Titanfall 2 has laser fields to prevent access to areas.^[19]
• X-Morph: Defense uses laser fences to kill off enemies.^[8]

See also

• Laser Doppler velocimetry
• Lidar