Theoretical analysis of terahertz wave parametric source based on intersecting cavity

摘要

The THz spectral region, lying between the microwave and the far infrared, is currently attracting widespread interest in relation to potential applications that span many areas of pure and applied science and technology such as in security, human health and communications. The development of practical source of THz radiation is crucial to the realization of these applications. Using optical parametric oscillator with intersecting pump results in compact, low threshold THz radiation source. Lithium niobate is one of the most suitable materials for generating THz waves efficiently because of its large nonlinear coefficient and its transparency over a wide wavelength range. In this communication we theoretically analyze generation of tunable terahertz (THz) radiation which is based on optical parametric process, in particular using a non-collinear quasi-phase matched geometry in the nonlinear crystal periodically poled lithium niobate (PPLN), and where wide and continuous tuning is obtained by changing the poled period and the angle between the resonated idler wave and the pump wave. Also the THz wave should fulfill the energy and momentum conservation laws. Furthermore, the bandwidth of the wavelength and the frequency of THz wave are analyzed. The optimal THz wave parametric oscillator for efficient coupling output power can be designed according to our theoretical results