hmm. strange, i was actually just thinking about this, trying to figure out the best way. IN MY OWN OPINION, i think taking it through carry-on would be more of a gamble than anything. You never know what they will do, but with some social engineering you might be able to. they always make sure you take out any electronics, and sitting there with a bigass laser (bigass because people are used to normal keychain ones, not ones that take 18650s) on the x-ray machine could be a no-no. If it where me, i would keep them home. But if you absolutely need to take them, i would either:
1.put them on carry-on, and keep them in whatever other bags/suitcases you have. I would wear a shirt that has something possibly to do with lasers, and if they take it out and question it i would say im going to a laser expo and point out the shirt
then show them the safety glasses next to it in the bag.
2. put them in a suitcase with the rest of your stuff, NOT on carry-on. keep the laser in its seperate own little box with a note that they could read, and a label that says <5mw
Lock BOTH boxes with a good lock (which can be hard to find, every small lock that might fit I've been able to pick in around 20 seconds, if not less) a combo lock might work better if there is no key hole
I cant promise you either of these will work, but i've been stopped for having a dozen meat probes (sharp thermometers) in my carry-on. Luckily, we had our BBQ-Brethren hat on - they understood and let us proceed
other times, we havent been so lucky. They actually took an (empty) butane and propane torch and deodorant and tooth paste from us before. Sad thing was, it was a half empty sample tube. yeah, imona definitely do some damage with that -_-
EDIT:
Yup no issues if you take the batteries and lens out. I also take out the heat sink with diode and driver too (as one unit) and pack it elsewhere in the checked luggage just to be sure. I wouldnt put it in carry-on.
:beer:
if hes done it, go with what he says