Terahertz optical scanning imaging of motionless polyurethane insulation materials

The authors demonstrate a terahertz optical scanning imaging system which utilises a combined 3D translation platform. Three mirrors are installed on the three sliders of the platform to realise the terahertz beam scanning of the motionless object. A pulsed quantum-cascade laser at the frequency of 4.3 THz and a fast quantum-well photodetector are employed in this terahertz imaging system to resea...