Terahertz Imaging With Quantum-Cascade Laser and Quantum-Well Photodetector

A transmission imaging system based on a terahertz quantum-cascade laser and a spectrally-matched quantum-well photodetector is presented. Terahertz imaging of paper money is demonstrated. An imaging resolution of 0.5 mm is achieved. This experiment demonstrates that the laser and the photodetector are potentially useful for imaging applications.