A new numerical model of terahertz parametric process is demonstrated, which takes the spontaneous parametric down-conversion into consideration by adding tens of frequency components in the coupled-wave equations. To set the values of some parameters in this model, the residual pump energy and idler spectra during spontaneous parametric down-conversion are measured experimentally for different pump energy and crystal lengths. Compared with previous models which only involve three waves, the new model is more accurate, especially when the seed power is low or the generated terahertz-wave is in the low frequency region.

中文翻译：

---

自发参量下变频的太赫兹参量过程模型

提出了一种新型的太赫兹参数化过程数值模型，该模型通过在耦合波方程中增加数十个频率分量来考虑自发性参数下变频。为了在该模型中设置某些参数的值，针对不同的泵浦能量和晶体长度，通过实验测量了自发参数下转换期间的残留泵浦能量和惰轮谱。与仅涉及三个波的先前模型相比，新模型更加准确，尤其是在种子功率较低或生成的太赫兹波处于低频区域时。