I plan on trying to recreate a version of Young's double slit experiment for a science fair. All the methods I've found for it recommend using a helium-neon laser. Would a laser pointer or some other cheaper laser work? For the slits my idea is to get a glass microscope slide, paint over it then scrape two slits off with an xacto knife. I jut tried using a laser pointer and a thin piece of card to split the beam, but I didn't really get an interference pattern. I think this was because the beam was to large. If nybody could recommend a good laser to use for this that would be great. Also if anybody has any suggestions regarding my idea for the slits I'd welcome them, but I think aspect of it should be fine.