Theoretical design of terahertz-wave parametric oscillator using LiNbO₃ crystal

A theoretical design has been made for terahertz-wave parametric oscillator based on the basic principle of optical parametric oscillator. Paper describes theoretical calculation method, based on phase matching conditions by using Lithium Niobate (LiNbO₃) non-linear crystal and this should also fulfill energy and the momentum conservation laws. To design the structure of terahertz-wave parametric oscillator, we have drawn the graphs of the relationship between the refractive index and wavelength when the frequency is in the terahertz region, analyzed the non-collinear phase-matching conditions of the terahertz optical parametric oscillator and draw the characteristics curves for LiNbO₃. The shape of the crystal and the angle of cutoff crystal, the tuning range, and also designed the optimal shape of the oscillator for efficient coupling output power.