Stupid question about "grid patterns"

Ok, this is an idiotic question... But I have to ask it.

I have seen people shining lasers into devices which split the main beam into many smaller beams, casting a grid pattern onto a surface. I would really like on, but a half an hour of googling has not been succesfull at finding out what they are called... I feel like an idiot for having to ask but... I dont know who else to ask and if anyone knows what they are and where to buy them it will be you guys.

I have a 1W 445nm hand held which I would like to use with it. Do I need anything special? Or will anything work? Are they expensive? If so can I make one?

Thanks!

PS: Mods please feel free to delete this thread and PM me if my ignorence bothers you.

What you're describing sounds to me like a "diffraction grating". Try searching using that term. Specifically, you want a "burst diffraction grating".

Wow. Just like that. That easy. WHERE DO YOU GUYS LEARN THIS STUFF?
You have no idea how hard it is to find one of these things without the proper name. Yes. A diffraction grating.

Thanks so much!
Feel free to delete this embarassing thread any time you like now.

Happy to help! And no matter how embarrassing you might feel that this thread is, I assure you it's neither the dumbest question I've seen here (not by a long shot) nor is it one that could never help anyone else.. so I hope no one deletes it.