基于反射式布拉格(Bragg)体光栅(VBG)的密集光谱合束是实现半导体激光器光纤耦合向高亮度发展的重要手段，建立了同时考虑发散角、光谱带宽、Bragg波长偏移量和Bragg角度偏移量的反射式VBG衍射效率计算模型。基于新建立的计算模型，提出了半导体激光器(DL)光纤耦合模块双波长合束的反射式VBG参数优化方法。结果表明：在优化选择的VBG参数下，DL光纤耦合模块双波长合束在满足入射光束(衍射效率大于90%的发散角14 mrad，半峰全宽为0.3 nm)中心波长偏移小于±0.49 nm，入射角度相对于Bragg角偏移小于±16 mrad的条件下，可达到大于98.7%的合束效率。

Dense spectral combining (DSC) based on reflection volume Bragg grating (VBG) is an important method to improve brightness of fiber-coupled diode laser modular. Accounting for laser divergence, spectral bandwidth, wavelength and angle shifts from ideal Bragg condition, a diffraction efficiency model of reflection VBG is presented. Based on the new numerical model of diffraction efficiency, design principles and technical approach for DSC of two channels by reflection volume Bragg grating are investigated. The results show if wavelength shift is less than ±0.49 nm and angle shift is less than ±16 mrad from ideal Bragg condition, the DSC combining efficiencies are over 98.7% when the spectral full width at half-maximum (FWHM) is 0.3 nm, and the divergence angle with over 90% energy is 14 mrad.