Some of them are, some of them aren't. There are obviously laser based ones that are easily recognizable as they produce a pattern of lines instead of a relatively evenly lit field. It's surprisingly difficult to find a picture of that, but I found a video that shows it well[1]. The ones that produce even illumination are probably LED based.

[1] https://www.youtube.com/watch?v=PIn00-qW5WI&t=1m34s