1961年,Franken发现倍频效应,产生了非线性光学。二十年来,人们做了大量工作,取得了很大进展。例如,借助于混频、参量振荡和受激喇曼等非线性过程,可以扩展相干辐射的波长范围,并在一定波长范围内实现了连续或准连续可调谐,使非线性光学的研究成果得到最直接应用。同时,非线性光学揭示了普通光 In 1961, Franken found the frequency doubling effect, resulting in nonlinear optics. In the past two decades, people have done a great deal of work and made great strides. For example, with the aid of nonlinear processes such as mixing, parametric oscillations and stimulated Raman, the wavelength range of coherent radiation can be extended and tunable continuously or quasi-continuously over a range of wavelengths, resulting in the results of nonlinear optics research The most direct application. At the same time, the nonlinear optics uncovered ordinary light