ABSTRACT
This entry describes some of the various characteristics and spectroscopic applications of widely tunable THz-wave sources based on parametric oscillation and generation of LiNbO3 via the nonlinear optical effect. Progress in THz-wave science is severely dependent on both the ease of use and the performance of the source. THz-wave parametric oscillator/generator spectroscopic systems are useful tools in this spectral range. These systems are accelerating the range of THz-wave research, including the spectroscopy of solid, chemical, and biological materials, semiconductor measurement, plasma diagnosis, atmospheric measurement, communication, radio astronomy, medicine, and so on.
