在铌酸锂晶体非共线相位匹配太赫兹波参量振荡器中观察到了级联光学参量效应。实验中测量到了一阶、二阶和三阶斯托克斯光。通过分析一阶、二阶和三阶斯托克斯光谱发现相邻阶斯托克斯光频率差相等，表明在太赫兹波的产生过程中发生了级联光学参量效应。在高阶级联光学参量过程中，一个泵浦光子可以产生多个太赫兹光子，表明在太赫兹波产生过程中量子转换效率会有效提高。

Cascaded optical parametric processes in terahertz parametric oscillator with a noncollinear phase-matching scheme based on bulk lithium niobate were observed. The spectra of the first-, second-, and third-order Stokes waves were observed. By analyze the spectra of the first-, second-, and third-order Stokes waves it is found that the frequency difference between adjacent-order Stokes waves is approximately equivalent, which means that the high-order cascaded parametric processes have realized. With high-order cascaded terahertz parametric processes one pump photon can generate several THz photons, which means that the quantum conversion efficiency can be enhanced.