Terahertz tomography system using fiber lasers and applications

High depth-resolution terahertz three-dimensional tomography was developed by monocycle-like terahertz pulses using ultra-short pulse fiber lasers. We designed novel photoconductive devices such as a thin-film LT-GaAs detector on Si substrates and an LT-InGaAs emitter for the monocycle waveforms. The depth resolution exhibited under 20 µm in the air and three-dimensional imaging was successfully obtained for multi-layer semiconductor devices.