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

Notes

1. http://www.freepatentsonline.com/3825916.html accessed 26 Jan 2011
2. Thomas Petruzzellis (1994). The Alarm, Sensor & Security Circuit Cookbook. McGraw Hill Professional. p. 145. ISBN 978-0-8306-4314-1.
3. Guth, Robert A (2009). "Rocket Scientists Shoot Down Mosquitoes With Lasers". The Wall Street Journal.CS1 maint: ref=harv (link)
4. Holden, Stephen. "Review/Film; A Futuristic Prison That Demands Escape". Retrieved 2018-05-11.
5. Ingenito, Vince (19 August 2016). "Deus Ex: Mankind Divided Review".
6. "Monaco: What's Yours Is Mine (Game) - Giant Bomb". Giant Bomb.
7. "Short Supply - Sly Cooper: Thieves in Time Wiki Guide - IGN". IGN.
8. "Combining tower defense with a shooter - game design implications".
9. "Laser bird deterrent increases crop revenue by 33%". www.laserfocusworld.com.
10. "Laser fence aims to protect crops from rats and other pests". www.laserfocusworld.com.
11. "LASER RAT FENCE wins €1.7m European Commission funds".
12. Bapat, Varsha; Kale, Prasad; Shinde, Vijaykumar; Deshpande, Neha; Shaligram, Arvind (2017). "WSN application for crop protection to divert animal intrusions in the agricultural land". Computers and Electronics in Agriculture. 133: 88–96. doi:10.1016/j.compag.2016.12.007. ISSN 0168-1699.
13. "'Laser walls' activated along India-Pakistan border to plug gaps in vigil - Times of India".
14. Congo (1995) - shootout scene in the woods on YouTube
15. Rudolf Kremers (21 October 2009). Level Design: Concept, Theory, and Practice. CRC Press. pp. 362–. ISBN 978-1-4398-7695-4.
16. "Laser Fence (Object) - Giant Bomb". Giant Bomb.
17. Hayley Camille; James Floyd Kelly (16 October 2015). The Ultimate Player's Guide to Skylanders Trap Team (Unofficial Guide). Pearson Education. pp. 8–. ISBN 978-0-13-421619-5.
18. "Chapter 8: Test Chamber 12 - Portal 2 Walkthrough". www.thonky.com. Retrieved 2018-05-11.
19. Hamilton, Kirk. "The Mission That Proved Titanfall 2 Was Something Special". Kotaku. Retrieved 2018-05-11.