基于钽酸锂晶体的太赫兹波参量振荡器运转特性的研究

Investigation of the operation characteristics of terahertz-wave parametric oscillator based on LiTaO_3

基于晶格振动模受激电磁耦子散射过程的基本原理,对由LiTaO3(LT)晶体组成的太赫兹波参量振荡器(TPO)的输出调谐特性、增益和吸收损耗特性,以及基于硅棱镜阵列耦合装置的THz波输出特性等方面进行了详细的理论研究和分析.研究结果表明,基于LiTaO3晶体A1对称性晶格振动的特点以及自身优异的非线性光学特性,通过利用短波长抽运光、适当提高抽运能量以及缩短TPO谐振腔腔长等方法,完全可以实现LT-TPO的高性能运转,证明了LiTaO3晶体是一种性能优良的TPO工作介质.理论计算结果及方法为以后的LT-TPO实验工作提供了详实的理论依据和实验指导.

Based on the basic principle of the stimulated polariton scattering process,the operation characteristics of terahertz-wave parametric oscillators （TPOs） using the LiTaO3 （LT） crystal,including the ability of frequency-tuning,THz gain and absorption coefficient and the output directivity of THz wave through the arrayed Si-prism coupler,is theoretically discussed in detail. It is found that the excellent performance of LT-TPO can be achieved through the employment of the short-wavelength pump,the high pump energy and short cavity for TPO,based on the characteristics of the A1-symmetry polariton mode and the outstanding nonlinear optical properties of LiTaO3,which is then proved to be a promising candidate material for TPO. The research results provide a useful guide for the future practical operation of LT-TPO.