Art painting testing with terahertz pulse and frequency modulated continuous wave

Paintings of individuals or collections undergo aging over time. The work of art restorers consists of repairing these defects using techniques that respect the history of the work. Ultraviolet, infrared and visible light and X-rays are well known techniques for analyzing these defects, but Terahertz is also increasingly used. Several works have shown that it is possible to detect hidden layers and various defects via terahertz pulses. In a previous work, we have shown that it is possible to use terahertz radiation to detect defects in the context of a restoration of a painting with a speed increase compared to time domain imaging.