They use X-ray diffraction to scan luggage at the airport.
Diffraction is most pronounced for light waves whose wavelength is similar in size to the diffracting object.
It produced a diffraction pattern instead of an image.
Michael Crichton -- The Andromeda Strain
He then removed a core sample measuring one centimeter in diameter and two centimeters in length from just below the right knee and analyzed it using an electron microscope, electron microprobe, mass spectrometry, X-ray diffraction, and X-ray fluorescence.
Malcolm Gladwell -- Blink
And most of that was from diffraction of the laser that was keeping it warmed.