ABSTRACT
We have long promoted research on the generation, detection, and application of THz waves using nonlinear optical effects at Tohoku University, RIKEN, and Nagoya University. We have tried various methods and crystals, but the optical parametric effects in LiNbO3 crystals, whose potential we recognized early on, have the best performance, showing high output, high sensitivity, wide tunability, and high dynamic range as a system. In this chapter, we describe the basic and recent progress of injection-seeded THz parametric generation (is-TPG) and backward THz-wave parametric oscillation (BW-TPO), which are the most notable results of our studies.
