I am building a laser maze for the family entertainment center that I own. The idea is that I have photocells set up in a room filled with fog. Lasers shine on the photocells and set off an alarm if a beam is crossed. I've seen this done before and kids love it. My plan is to use eight red lasers and two green lasers for now, and once the room starts making money, upgrade the red lasers to green ones (we're on a tight budget at the moment). The room is 14 feet wide by 14 feet long, so the lasers won't have to travel too far.
I need help with what laser modules I should get. The trick is that the lasers could potentially be on continuously for several hours at a time if the maze gets used a lot. So my main concern is the duty cycle of whatever laser modules I use. I can heatsink the modules to some extent, but whatever I use has to be pretty compact because I'm mounting these lasers on the walls and can't have something sticking out too far for kids to run into.
I know that I don't need anything stronger than a 5mW green module to see the beam clearly with the fog, but what about a red module? Would a 10mW red module be too much of a safety concern? Would a 5mW red module be good enough? I'd really like to buy my modules from AixiZ if any of their stuff will work for me.
One last thing - I'm very concerned about safety, since we'll have little kids going through the maze. Do I need to install IR filters on all of the laser modules just to be sure that no one gets hurt?
I really appreciate any help that anyone can send my way. I have lurked quite a bit through this forum and have found lots of great information. Thanks in advance.