Prediction of Coherent Optical Photons from Shock Waves in Crystals

In this work, we study the electromagnetic radiation emitted by the propagation of a shock wave through an ionic crystal, NaCl. Our analytical theory and computational experiments predict that under some conditions, weak yet measurable temporally coherent light can be observed emerging from the crystal, typically in the range 1-100 THz. The radiation is generated by an oscillating dipole-like material polarization resulting from the nonlinear synchronized motion of large numbers of atoms induced by a planar shock wave propagating through the crystalline lattice