A High Dynamic Range and Spectrally Flat Terahertz Spectrometer Based on Optical Parametric Processes in LiNbO$_{3}$

A wideband, wavelength tunable, spectrally flat terahertz (THz) spectrometer with a dynamic range in excess of 70 dB was demonstrated. The emission of THz-wave was achieved using an injection-seeded THz parametric generator (is-TPG), and detection was achieved using nonlinear optical wavelength conversion, both in magnesium-oxide-doped lithium niobate crystal. This system has potential applications in non-destructive sensing and imaging of a wide variety of materials.