Scientists make holograms of atoms using electrons: In their experiments, the scientists beamed an intense infrared laser light at an atom or molecule, which resulted in the atom or molecule becoming ionized and releasing an electron. The laser field causes the liberated electron to oscillate away from and toward the ion. Sometimes, an electron and ion collide, releasing a very short burst of radiation.
Because the electron motion is fully coherent, meaning it always has the same phase, the scientists realized that they could apply holographic techniques to record information about the ion and electron. The key to holographic electron imaging is to observe the interference between a reference wave (which is emitted by the electron and doesn’t interact with the ion) and a signal wave (which scatters off the ion and encodes its structure). When the reference wave and signal wave interfere on a detector, the encoded information about the electron and ion is stored and can be viewed in the future. As the scientists explained, the result is a hologram of an atom produced by its own electrons.