多路激光体布喇格光栅光谱合成特性研究

为了研究多路激光体布喇格光栅光谱合成的合成特性,采用建立多路反射式体布喇格光栅光谱合成系统物理模型的方法,得到了具有不同谱宽的光束的衍射效率曲线,以及体布喇格光栅材料的吸收系数和通道间的串扰对总的合成效率的影响曲线。结果表明,在入射光束中心频率不变的情况下,随着光束光谱宽度的增大,衍射效率逐渐减小;随着光束中心频率与光栅中心频率之间偏移量的增加,衍射效率逐渐减小;当光束谱宽与光栅光谱选择宽度大约相等,并且通道之间的间距较小时,通道之间由于发生串扰而损失的衍射效率需考虑,随着合成路数的增加,总的合成效率受体布喇格光栅材料吸收系数的影响越来越大,而受串扰的影响则几乎保持不变。

Study on multi-channel spectral beam combined characteristics based on volume Bragg gratings

In order to study the combined characteristics of multi-channel spectral beam based on volume Bragg gratings(VBG), after building a model for the spectral combining system of multi-channel laser beam by reflective VBG, the diffraction efficiency curve of different beam spectral width was obtained, and the total combination efficiency curves affected by the absorption coefficient of VBG and the cross-talk between channels were also obtained respectively. Numerical results show that diffraction efficiency decreases with the increase of spectral width of beam under condition that the central frequency of the incident beam remains unchanged; diffraction efficiency decreases after increasing the offset between central frequency of incident beam and the central frequency of VBG; the diffraction efficiency of loss due to the cross-talk between neighboring channels should be considered under the condition that the spectral width of incident beam and the spectral selective width of VBG are approximately equal and the condition that the space between neighboring channels is smaller, with the increase of the combination channels, the effect of the absorption coefficient of the material on total combination efficiency gets larger, but the effect of the cross-talk is almost unchanged.