体全息透镜依据体光栅的布拉格选择性，能够对物体的三维信息进行逐层恢复。利用点扩展函数对体全息成像系统的深度分辨率进行分析。分别用球面参考光和平面参考光记录两种典型的体全息光栅，并把它们分别作为体全息透镜安置于成像系统中。通过改变探测光源的位置来对体全息透镜，纵向与横向分辨率进行研究，并且对于透镜参数对分辨率的影响也进行了讨论。实验结果表明，半径较大的体全息透镜具有较好的深度分辨率，成像效果较为清晰。球面参考光体全息透镜对于微观物体成像的分辨率特性要优于平面参考光体全息透镜，更适用于微观成像系统。

A volume holographic grating lens can reconstruct the three-dimensional information by collecting multiple optical slicing of an object according to Bragg selectivity of the volume holographic grating. Its imaging resolution was analyzed by using the point spread function of volume holographic imaging system. The volume holographic gratings were recorded by using two mutually coherent beams of a spherical reference beam (SR) and a planar reference beam (PR), and were used as volume holographic imaging lenses in the imaging system. The longitudinal and lateral defocusing characteristics of volume holographic lenses with SR beam and with PR beam were investigated experimentally by displacing the interested objects away from original reference location, respectively. The effects of the parameters of the volume holographic lens on the longitudinal and lateral resolution were also discussed. The experimental results show that bigger size of the volume holographic lens can obtain better depth resolution, and thus the results of imaging are better. Since the imaging resolution of SR volume holographic lens is better than that of PR one, it is the better choice to adopt a volume holographic imaging system with SR lens for microstructure imaging.