Doing a project on Lasers, Need Help don't know anything about them!

Hello All,

I just made an account here and just found this website. I am doing a final presentation on hypothetical research on lasers as in we arent building on just explain what laser light is, the components needed to make on and what they do. So we have one slide we want to use as our Hypothetical Research slide... I was wondering is there a way to calculate how strong of a laser and what color of a laser we would need to a. burn a match b. burn someone retina c. cut through steel d. pop balloons e. show on the moon f. kill a person. I have seen lots of numbers like you need this powerful of a laser to burn a match etc, but how can we actually calculate that number?

Please any help would be amazing thank you so much. Also if this is impossible to do, anyone have any other hypothetical research things we could do with just equations and calculations. Thank you so much again.

- A Desperate Physics Lab 116 student

Laser function and theory is easy for (most of us) to convey, but as for quantitative measurements of how much power is needed to do X damage, that is almost entirely unavailable. Most of that kind of data is anecdotal and entirely not based on any math what so ever. The most I can think of is there is a figure of intensity that the US Govt' declares as maximum allowable to enter the human eye without causing permanent damage. I believe it was based on sunlight. I can't remember the details, sorry.

The power density needed for X damage at Y wavelength varies based on the absorbance spectra of the target material. No one wavelength inherently delivers more thermal energy than another to a uniformly absorptive target if the power densities are identical.

You could do something where you determine the cavity length needed to bring about different transverse modes of operation within a laser. That IS heavily math based and entirely founded in hard science. I don't know of any of it so I can't help, sorry. Look up TEM modes for more info.