Wow! Lot of interesting information! Interesting job too. Thanks for providing this :)
Laser induced break-down spectroscopy is not new stuff- hand held detectors stuck into samples of substances have been around for a while. Stand-off is the long pole in the tent so to speak- exciting chemicals beyond a few centimeters is hard to due (the lasers in hand held devices are not very powerful, and the spectrometer input is nearly contact with the sample). Sending enough energy via laser to a distant target makes for an unsafe laser ( eyes, burns skin etc, ablates metal/paint etc. Of course, detecting the excited light energy given off the sample is key- an optical telescope is subject to interference, dust, smoke, temperature variations in the space between lens and target, let alone the lens itself.
The Army found that the most efficient tool used for standoff detection of IEDs was the M1 Eyeball coupled to a brain trained to look for anomalies or “is it the same or has it changed” human observers operating on routes etc. detecting VBIEDs at check pints was basically a risky business- stopping and inspecting well outside standoff distance was key- making the operator turn on his lights, washers, horn and other accessories was found out be useful in pre-detonating bad guys....
The counter IED cycle was vicious, we defeat one technology, they employ another, we defeat that they deploy another eventually retuning to the original dumb wires and victim activated traps.