基于体布拉格光栅的光谱合成的数值分析

 建立了分别用一个和两个反射式体布拉格光栅实现两路和三路光束合成的物理模型，模型中考虑了体布拉格光栅的吸收，并假设入射光束的光谱具有高斯线型。通过对两路和三路光谱合成的数值分析可知:当光谱宽度为0.1 nm时，两路和三路光谱合成的效率分别为98.76%和97.69%;当光谱宽度为0.3 nm的时候，对应的效率分别为97.34%和95.78%。随着光谱宽度的增加，合成的效率明显降低。当光谱宽度较窄时，实现多路光束较高的合成效率是可行的，这为高能激光的获得提供了一种确实可行的方法。

Numerical analysis of spectral beam combining by volume Bragg grating

The physical models of spectral beam combining for two beams and three beams by one and two reflective volume Bragg gratings(VBG) are founded in this article. The physical models consider the absorbability of VBG and suppose that the incident beam has a Gaussian shape. Two and three spectral beams combinings are numerically analyzed. When the spectral width is 0.1 nm, the spectral beam combining efficiencies are 98.76% and 97.69%, and when the spectral width is 0.3 nm, the spectral beam combining efficiencies are 97.34% and 95.78%, respectively. The increscent spectral width decreases the spectral beam combining efficiency. The results show that the high spectral beam combining efficiency for more beams can be obtained by this method, which provides a doable way for high power laser.