Three-Dimensional Wide-Bandwidth Quantum Energy Truncation Terahertz Coherence Tomography

We report a quantum energy truncation terahertz coherence tomography technique that enables highly localized extraction of molecular-species-specific THz responses. The method exploits resonant photon loss when the emitter THz energy matches molecular vibration quanta. Reflected THz radiation is recorded and mapped into depth-coded image sequences, from which subsurface structural information and molecular fingerprints are retrieved to construct three-dimensional tomograms. This approach resolves major limitations of conventional continuous-wave (CW) THz imaging—namely, its lack of spectroscopic specificity and dependence on angular scanning—by directly correlating molecular excitation spectra with depth information. As a result, quantum energy truncation terahertz coherence tomography enables rapid, three-dimensional THz imaging with selective sensitivity to discrete molecular quantum energy transitions, providing new opportunities for nondestructive characterization of material refractive indices, molecular composition, and subsurface structures.