Optoelectronic-based high-efficiency quasi-CW terahertz imaging

We demonstrate an optoelectronic-based high-efficiency terahertz (THz) imaging system. Based on a micron-sized photonic transmitter operating at room temperature, an improved signal-to-noise ratio with a reasonable spatial resolution can be achieved. Biomedical THz imaging was demonstrated with a dried seahorse and a fresh flower, which were hidden in plastic sample holders and were invisible. Tissue and water distributions of distinct regions of the bio-samples were clearly resolved, showing the high imaging contrasts of the demonstrated system. These results reveal the possibility to construct a high-sensitivity THz imaging system with less than 1-mW optical excitation.