another way around that should be to have a commercial invoice included in the box with the correct Schedule B Number for the item being shipped. The Schedule B Number is a number that the US Gov uses to universally catagorize the contents of a box without having to inspect it themselves. And believe me they sub-catagorize the sh!t out of things.
http://www.census.gov/foreign-trade/schedules/b/2007/index.html
is a complete list of the Schedule B Number's for 2007 (yes they change every year) but for the most part only 10-20% of the list numbers actually change each year.
after looking through the different schedule B's available I believe this is the correct one for the types of lasers we are talking about
8456 Machine tools for working any material by removal of material,
by laser or other light or photon beam, ultrasonic, electro-
discharge, electro-chemical, electron-beam, ionic-beam or
plasma arc processes:
8456100002 Operated by laser or other light or photon beam processes No.
8456200000 Operated by ultrasonic processes . . . . . .No.
8456300000 Operated by electro-discharge processes . . .No.
845690 Other:
8456903000 For working metal . . . . . . . . . . . .No.
8456907000 Other . . . . . . . . . . . . . . . . . .No. <----------- this would be the one we want since it's powerfule enough to "remove material" but not designed for a specific use
now if it's lower powered there is a number for Lasers used for presentations
851310 Laser pointer, for presentation
and even one for you CO2 laser people out there
851580 Welding machines, laser powered or ultrasonic powered
I hope this helps, I don't know much about the whole FDA thing but from an international shipping aspect, Via DHL this is all you really need, unless the shipment is over $2500, but thats a different story.