Can IR Lasers be made Safe?

[krich]

I'm looking at making a long range break beam sensor, of sorts, and would like to use a modulated laser. It would be nice to use an IR laser, because I don't want the red visible glow. I worry that I won't be able to make the IR laser reasonably eye-safe. I've done much reading on the topic and am aware that IR doesn't cause a blink reflex and can therefore be orders of magnitude more dangerous than an equivalently powered visible laser.

Is there any acceptable power, or premade laser module that is generally eye safe? I'm not talking about safe for extended exposure. Just as safe as your average <5mW red laser while taking into account the lack of a blink reflex.

Can any IR laser be made reasonably safe?

 

[crutschow]

IR lasers can be safe if their power is low enough. See Laser safety - Wikipedia, the free encyclopedia for a discussion of laser safety levels.

 

[mneary]

Without a requirement to be coherent, an IR LED is probably as useful as a laser. Lasers don't usually need an external lens at the emitter, and an LED would need one, but I think that's your major difference.

To reduce average power you would pulse it, at as low a duty cycle as you can. This gives your detector a big signal to filter out of the background.