Can multiple convex lenses focus a laser beam to burn paper?

[Scienceislifeforme]

I want to make a laser to burn paper so if i use 2 or 3 convex lenses with a laser will it be helpful . Or can i use 1convex then 1 concave and then 1convex to make it

 

[nasu]

Why would you use a concave one?

 

[berkeman]

I want to make a laser to burn paper so if i use 2 or 3 convex lenses with a laser will it be helpful . Or can i use 1convex then 1 concave and then 1convex to make it

Welcome to the PF.

You should probably just stick with using sunlight and a magnifying glass. A laser with enough power to start burning a spot on paper would cost many thousands of dollars. If you are in university, you may be able to ask the appropriate physics professor for a tour of the laser lab...