Cascaded parametric down-conversion on backward terahertz-wave parametric oscillation

Abstract

In recent years, terahertz-wave researches have made remarkable progress toward practical applications through vigorous R&D in both the photonics and electronics fields. Backward terahertz-wave parametric oscillation (TPO) is a novel TPO with compactness that produces high-power terahertz-wave output simply by injecting near-infrared pulsed laser into an artificial periodically poled lithium niobate (PPLN) crystal. Potentially, the broadband frequency tunability that continuously covers the sub-THz frequency range would be expected. Recently, basic experiments for imaging applications have also been started. In this paper, we introduce the cascade conversion, which improves the quantum conversion efficiency.