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Q & A: making a flashlight laser?

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Most recent answer: 08/22/2015
Q:
how to convert a torch flashlight into a light beam resembling to that of a laser light
- Nishant Singh (age 18)
Sultanpur, Uttar Pradesh, India
A:

You can't. Lasers have a particular special property of having coherent light as opposed to an incoherent mixture from different sources. This allows a laser light beam to remain almost as collimated (heading just one direction) as is mathematically possible for a beam of its width. The flashlight beam (unless your flashlight has a laser in it, as some now do) is not coherent. If you focus it down to a narrow waist, it will have to spread out much more than a laser beam would as it goes farther.

Mike W.


(published on 08/22/2015)

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